12 Geisha coffees

Geisha is a botanical variety of the arabica coffee and is priced markedly higher than other great specialty coffees. Geisha has a big reputation for it’s great taste. A few years ago it was still very rare. So few people had tasted them.

The reputation started with the coffee farm Esmeralda in Panama. They have been doing auctions since 2008. Almost every year the top lot achieve higher price. Of course other coffee farmers saw the high prices and wanted to plant them as well. In the recent years a lot of Geishas from different countries have hit the marked.

That made me wonder:

How different are they ? Normally there is more to the taste of a coffee than the botanical variety.

And … how good are they ? How much is just hype ?

I had tasted the famous Esmeralda farm Geisha some years ago at The Coffee Collective here in Copenhagen, Denmark – and I did find it extraordinaire; very complex and dense in the taste. Impressive. But as prices was rising I was wondering about how overpriced they were.

How to do a comparison ?

When roasteries sell Geisha coffee it is often markedly more expensive than other coffee. Of course, since the green bean price is higher. Normally from a green bean company you can get samples. But rarely on the Geishas. If you want to participate in the Esmeralda farm auction you can buy samples for $ 300 ! Or that I heard some years ago.

My way of doing this is to ask around in the Danish coffee community if people want to join forces (money) and buy Geishas together for a cupping event.

They were game. Quickly we were 17. And some on the waiting list.

We bought coffees for more than € 400 !! The most expensive coffee tasting I have ever done.

Francesco Impallomeni invited us to do the cupping at Nordhavn Coffee Roasters, here in Copenhagen. Thanks for hosting ♥

Francesco-medpilPhoto by Gitte

Picking Geishas for the cupping event

We limited ourselves to 12 different coffees. Too many coffees can be overwhelming. A pity that good coffees drown in a crowd.

We selected them to try different countries, different processing (washed/natural/honey) and different roasteries. John Lindgreen and Andreas did the research and picked the coffees.

I got hold of one Geisha in green beans, 1 kilo. This we wanted to explore in different roasts.


We got 4 different Panama Geisha. At first no one had Geisha from the famous Esmeralda farm for sale. But when The Coffee Collective heard about our event they donated us 15 grams of Esmeralda. Just enough for one cupping cup.

Coffee farmers in Costa Rica had been quick to plant Geisha coffee. So much Geisha comes from there. We got hold of 5 Geishas from Costa Rica; different processing (red and white honey, washed and semi washed) and different farms.

Then we had 4 other countries with one coffee from each: Colombia, Bolivia, Honduras and Ethiopia.

Regarding the Ethiopian: it wasn’t a Geisha like the others. We expect all the other coffees to be the same botanical variety – gotten from Panama. But the Geisha variety grown in Panama for the past 100 years was imported from the Gesha area in Ethiopia. The same area where the Gesha Village coffee farm is situated today. Their coffee trees are from the local area. So the two kinds probably have similarities but may also have differences in the DNA.

The last round was one bean from Costa Rica; Santa Teresa, white honey. But in four different roasts. I had gotten hold of 1 kilo of green beans and had roasted 200 grams at a time.

I had heard that Geisha is only special in a very light roast. If you roast it darker it will be more ordinary. I had no idea exactly how far that was. But started by giving it 1 minute from first crack (=Development time =DT). I found it got dark very quickly. I tasted it 5 days later and found it a bit lighter. So I ventured shorter with the next roast: 45 seconds DT. Again tasted 4-5 days later. It could bear shorter. So the next batch I did 35 seconds. It seemed thinner. So I wouldn’t go shorter.

On the other hand, I wanted to explore “how to ruin a Geisha”. How little longer would it need to get boring ? My guess was 1:30 minutes DT.

The water

Here in Denmark we have great water from the tap. Very clean. It is just very hard = high in Calcium Carbonate (you can see the formation of lime scale in your kettle). That mutes many tastes in coffee. Especially in light roasted coffee.

So if you are enthusiastic about coffee you use filtered or spring water for coffee brewing. But that can be done in many ways.

So a few days before the cupping event; we tested 4 kinds of filtered water. We tested it on the Bolivia Geisha from The Coffee Collective. One of the waters was the one used for the espresso machine. That was the worst of the 4 waters. It made the coffee taste boring. The aroma of the coffee came out in the 3 other cups, but here it was muted.

With the two best waters one had a higher Calcium content – and that gave a little dryness to the coffee. The other had higher Magnesium and made the coffee taste the best.

This water had these specifications (in CaCO3 equivalents):
Magnesium 53 ppm
Calcium 55 ppm
HCO3- 54 ppm

So the ratio the KH to GH ratio was 1:2.
KH = Carbonate hardness
GH = General hardness (Magnesium plus Calcium)

The bottled water we started out with (Denice) had 117 ppm HCO3- But we lowered it by adding 7,2 mg citric acid per liter.

Such small amounts are difficult to do precise on a scale. So Andreas made a concentrated citric acid solution – and used a syringe to get the right amount for each 2 liter bottle:


Note: We didn’t test all kinds of water. Just the ones that would be operational for us to use in this cupping.

Grinding and dosage

When we tasted the water, we used a grinder in the roastery. But Andreas could remember that the Bolivia Geisha coffee tasted better with an EK43 grinder. Sweeter. Clearer aromas. So we brought a EK43.

EK43grindingGrind size: a bit finer than for drip coffee.

Dosage: 60 gram pr liter

We had 3 cups of each coffee because we were 17 people. We made 3 cupping spots with 5-6 people at each.

How did they taste?

First of all: you should always be careful not to judge a coffee from a single tasting. Different coffees are the best at different brewing techniques.

Here we opened the coffees on the day of the cupping. But some times a coffees get better a couple of days after opening – must be that a little oxygen does something good for taste at first.

But still it is useful to compare coffees like this – because differences stand out more clearly than when comparing out of memory.

The downside to having an all Geisha cupping is that the similarities won’t stand out. When I earlier have tasted Geishas, it has been the only one on a cupping table with other kinds of coffee. And each time the Geisha has stood out as something special: the taste was very “filled out”/ rich. And they had much sweetness.

PeoplecuppingtableWe tasted the coffees four at the time to avoid overload. To have enough time to focus on each coffee as they cooled down. That gave 4 rounds:

Round 1 “4 countries”

We started with this round because we expected here would be the biggest difference.

No 1: Bolivia – Takesi – washed.
Roasted by The Coffee Collective, Denmark

No 2: Colombia – Finca Rosenda – Washed.
Roasted by Ditta Artigianale, Italy

No 3: Honduras – Caballero – Washed.
Roasted by Tim Wendelboe.

No 4: Ethiopia – Gesha Village – Natural.
Roasted by Gardelli, Italy

The Bolivian and Ethiopian stood out.

The Bolivian had a very deep smell. Tasted very fruity (raspberry and abricot), soft, sweet and tea like. When it cooled a nice acidity came out and it had a hint of Ethiopian bergamotte.

The Honduras reminded me of a washed Ethiopian coffee. A roaster, Kenneth, described it as bergamotte but a bit herbal – and it was missing floral notes.

Gitte had it as her favourite in this round – she described it as chocolate and vanilla . Andreas said hazelnuts and honey melon.

The Colombia was weaker in the aroma than the others – and had bitterness. I would tend to think it was roasted too dark. When it was warm I found some caramel in the taste. Right after I found they also wrote that on the bag. It also said Tangerine. I found that as it had cooled down.

On week later a few of us tried it again in cupping. This time it was much better. I liked it.

The Ethiopean Gesha Village: Andreas and Francesco had it as their favorite of the whole cupping. It had a strong natural taste. To me it dominated it all and I didn’t find it interesting. It really divided people; they either really liked it or really didn’t. Very typical for naturals.

By the way; when the coffee had cooled all the way to room temperature the natural taste was more discreet/less pronounced – and I liked it better. Andreas liked it very much and as it cooled down he found: violets, honey and blackcurrant. Kenneth said; lime fruit.

Those who didn’t like it called it over-fermented or like olives.

By the way – the Ethiopian and Bolivian coffees had the highest cost per kilo of all the coffees.

Round 2 “Panama”

No 9: Panama – Ruiz family – Natural.
Roasted by Horsham Coffee Roaster, UK

No 10: Panama – Finca Hartmann – Washed.
Roasted by Ditta Artigianale, Italy

No 11. Panama – Finca Hartmann – Natural.
Roasted by Ditta Artigianale, Italy

No 12: Panama – Esmaralda – Natural.
Roasted by The Coffee Collective, Denmark

Even though 3 of these coffees were natural they didn’t have the strong natural aroma as the Ethiopian in round 1.

They were all very good. We agreed that this was the best round.

No 10 and 11 was from the same farm, Finca Hartmann – just different processing: washed and natural. We found the washed to have “classic Geisha taste”.

Kenneth noted no 10 as jasmin, green grapes, melon, coconut, nice sweetness and acidity. Funny enough he found the jasmin only when it was warm – where as the natural processed no 11 from the same farm, he first got the jasmin when it had cooled. No 11 he also found had plum and raisin. At a little strawberry jam at first – for him a typical sign of natural process.

John had the natural (no 11) as his favorite of the whole cupping. Gitte had no 10 as her second favorit of the whole cupping.

No 9 from the Ruiz family: here some said it was roasty. As it cooled down it became my favorite of the whole cupping. It had some very seductive aromas. Kenneth got some unpleasant bitterness when it was warm. But as it cooled it disappeared and he found it amazing – with warm spices (like cloves).

We cupped it a week later in both 60 and 50 grams per liter. It was the best in 50 g/l. This time the flavor was more funky and had a tast of heavy rum.

The Esmeralda: More than 10 people liked it the best. Roaster Ida Kofod from largest specialty roastery here in Denmark, Kontra Coffee said it was among her ALL TIME favorites coffees: “This coffee has everything! Totally balanced, sweet, acidic, bitter, heavy, thin, juicy, fruity, I could go on. A very complex and clean cup, I love it.”

Kenneth was also blown away: It stood out from the rest. So clear apple acidity. Great sweetness. So complex. So many fascinating aftertastes. Light years ahead of other good coffees. Perfectly roasted coffee. He felt overly stimulated here.

The funny thing was … when I first tasted it, I thought something was wrong. A defect bean or something. Because to me it had a bad taste, like vinegar/acetic acid. Andreas got the same. This just underlines how different we taste. Two of us have a receptor for some compound that the other 15 people didn’t have. But I had earlier tasted Esmeralda coffees were I was very impressed, so it might just be this particular coffee I had a problem with.

We concluded that Geishas grown in Panama are something special. And we think that the high auction prices at the Esmeralda farm are not pure hype.

Kenneth remarked that the Peterson family put a lot of work into making the coffee at the Esmeralda farm. So if you want to make great coffee there is no short cut in just planting a Geisha coffee.

After the cupping I talked to The Coffee Collective. They told me that this Esmeralda lot was the wildest tasting coffee they ever had. They had the same experience as us: Some did not like it – but most of them loved it and was in heaven. So they asked the Peterson family if they could reproduce that coffee; make the same taste next year. They said no. There had been some weird wheather conditions during the processing. They found the taste so different so the lot wasn’t a part of the auction.

By the way – The Coffee Collective also found vinegar in the taste (as Andreas and I).

Round 3 “Costa Rica”

No 5: Costa Rica – Doña Daisy Finca Don Pepe – Red Honey.
Roasted by Has Bean, UK

No 6: Costa Rica – Finca El Potrero – white honey.
Roasted by Has Bean, UK

No 7: Costa Rica – La Candelilla – washed.
Roasted by Gardelli, Italy

No 8: Costa Rica – Montebrisas – Semi Washed.
Roasted by Ditta Artigianale, Italy

We were a bit disappointed in this round. They were not as good as the Panamanian coffees. But that was also was also difficult to follow.

The first two from Has Bean we found too dark (but not as dark as Has Bean normally roasts, some remarked). Could have been interesting to see if they would have had more aroma at lower dosage. Maybe 50 grams per liter instead of the 60 we did here.

We tried that a week later. It was better in 50 g/l. More flavors came out. But to me it was still a bit too dark roasted.

Everybody found something was wrong with the La Candelilla coffee. It was hay like/grassy. One asked if it was an older crop. No, it was from 2017. The bag didn’t have a valve. So, the CO2 release made the bag a balloon (close to exploding).

I tried it several times in the following week hoping to crack the code for brewing it. But it was difficult.

Gitte had no 8 Montebrisas as her favorite in the whole cupping. When I tasted it again a week later I could agree with her. It had both the depht and a light aromas underlining the pleasant acidity.

Kenneth felt he didn’t give these Costa Ricas time enough. He was so blown away after the Panama round. His favorit in this round was no 8 Montebrisas. In general Costa Rica coffees are more delicate, he thinks: you have to work more on roast and the brewing.

By the way – the two Has Bean coffees had the lowest cost per kilo of all the coffees.

Round 4 “Different roasts of the same bean”

12.  Costa Rica – Santa Teresa – DT 35 seconds
14. Costa Rica – Santa Teresa – DT 45 seconds
15. Costa Rica – Santa Teresa – DT 1 minute
16. Costa Rica – Santa Teresa – DT 1:30 minutes

People agreed all four roasts tasted very different . And that the aroma was  different from the panamanian Geishas. It had notes of roasted hazelnuts and butter. It was very sweet but maybe too much.

People had different favorites among the first three. Almost equally distributed on the 35 secs, 45 secs and 1 minuts roasts.

Everybody agreed that the 1:30 minuts was too dark. Bitter, burnt and hardly any of the aroma. But again, the question was: would it be better at lower dosage ? We didn’t get around to that. But we did make an espresso with it. And it turned out good. Almost perfume like aroma.

Two persons at the cupping prefer some bitterness in their coffee. But even for them the DT 1:30 minuts was too much. They liked the 1 minute roast the best.

Some of the participants had high bitter sensitivity. Or rather; can taste types of bitterness most of us can’t. They found the DT 1 minute bitter. And they liked the 35 seconds the best. They found it had the highest sweetness. I too liked the 35 seconds the best.

To me who had roasted them and tasted along the way to plan the next roast … this coffee is the sweetest I have ever had. And it had a very distinct roasted hazelnut aroma (like in the Nez du Café aroma kit). I don’t think I have met such a powerful hazelnut aroma before.

Therese and Andreas


Just because you buy crazy expensive Geisha beans doesn’t mean you get great coffee automatically. You must work for it.

Do Geishas planted in other places than Panama have the same taste ?
No. Other factors like climate and soil does influence the taste. They are not all floral. But they seem all to have much sweetness.

Processing of course also influence. But the naturals from Panama were among the best naturals we have tasted.

Is the pricing of Geishas hyped ?
We think so. You can get other great tasting coffees not quite as expensive. But the famous Esmeralda farm in Panama do a good job, so we don’t think their high auctions prices are pure hype. There is a reason they are still high despite the increasing supply of Geishas from other farms. In Kenneths opinion they are light years ahead in making good coffees.

But even though there is an element of hype in the market for Geisha, I don’t think the hype is that bad. It is a driving force for the marked of high quality coffees. The hype makes buyers pay more for coffee. And the high prices makes it worth while for the coffee farmers to strive to produce superb coffee.

What I have heard from others

A Danish guy visited a Geisha farm in Panama last year. He said they  roasted Geisha only 20 seconds from First Crack.

A Danish coffee farmer in Mexico told me that Geisha grown lower than 1,500 meters is not interesting.

Norwegian roaster Tony Jacobsen writes about his experience with Geishas:
“We have had Geisha private reserve from Hacienda La Esmeralda and i have tried Geisha from Geisha Village, something from Ninety Plus, i have tried the geishas from Panama Varietals. And they are all unique in their way. Now we are actually importing a Peru Geisha, getting it by plane, hopefully next week. I remember Hacienda Esmeralda from 2007 Kaffa, it was a game changer. I love geishas, they are hard to roast as you mention. But if you get them right, they are the most amazing coffees from South America. Overpriced yes, but i guess it has its market. I like them clean, not naturals because of the botanically qualities as the sweetness – that i want to come from the bean and not the processing. But the floral notes are like catching butterflies in my mindset.”




Light versus dark roast

Tasting light roast for the first time is strange for many coffee drinkers because something is missing compared to the darker roasts.

But many coffee people loves it because it has some great flavours that dark roasts don’t have.

Boenner uens overflade 12sep2016

But light and dark roasted coffee are not only different in taste but also to work with. So if you treat a light roast like a dark it won’t taste good. And the other way around.

If you are curious to try there is a few things to know. Because they are different to work with. Below is a list with the differences. We also talk about this in Episode 8 in the Coffee Roasting Navigated podcast.

Fil 15-08-2017 09.11.02

There is no common definition of when exactly a roast is light or dark. In the U.S.A. it is common to call it a light roast when stopped before the Second Crack, but still having completed First Crack. Here in Northern Europe that would be considered a medium roast. We call it a light roast when it’s stopped before the First Crack is over – or just around the end.


List of differences

Comparing dark coffee roasted to 2nd Crack versus light roasted stopped before First Crack is over or just around the end.

1. Roastingbeans-trier-sh1
Not all beans taste good in a light roast. High grown beans is a good place to start if you want to explore roasting light.

Not any light color roast taste good. You have to explore to find what roast profile suits the given bean.

2. Dosage
This is mainly for filter/drip and french press. Regarding espresso go to #7.

When you brew a light roast: updose = use more coffee.

Light roast has less solubles than dark roast. So you need more grams of coffee.

Exactly how high dose depends on the roast and what you prefer in the taste – so go explore.

When I brew a light roast filter/drip or french press – I mostly use a dosage around 60 grams pr liter  – but goes from 55 up to 70 grams pr liter depending on the coffee. It’s different where they are the best. I even know people who do 85 grams pr liter.

Darker roasts are better at lower dosage. I have even heard of people using dark espresso roast as low as 35 g/liter.

3. Grinding
Grind light roasts finer than for dark roasts. I don’t know if it’s because light roasts are less porous or again this less-solubles. But you get more of the good taste by grinding finer.

Because of the denser bean structure, I use a longer bloom phase when making drip coffee (V60, Kalita): 45 seconds instead of 30 seconds.

4. Brew water
If your tap water is hard = has a lot of chalk … then it can make a light roast brew taste boring – compared with filtered water. This is a whole science in itself. Look up “third wave water”


5. In the cup
When you taste it – pay attention to how the taste change as the coffee cools in the cup. Very light coffee do not have much taste around 70ºC but get interesting around 50ºC.

6. Milk and sugar
Be cautious with the milk. Some light roasts taste great on it’s own … but if you poor milk into it: the interesting taste will all be gone. Because the flavors are so delicate.

The same with sugar. Lighter roasts can be sweeter in itself than darker roast. So taste before you ad anything.

7. Espresso
Brewing espresso of a light roast is different than with darker roasts. There are different approaches. But a few things people agree on:

espresso brygningUse a large basket in the portafilter, size 18 or 21 grams for 58 mm. Light roast doesn’t seem to work well in smaller pucks.

Use longer preinfusion.

Traditional in espresso you have a rule of thumb saying: reach 1:2 brew ratio in 25 seconds. So if you have 18 gram coffee → then get 36 grams in the cup. That doesn’t seem to work with light roasts: it’s sharp, sour and do not get the aroma of the given coffee.

Again bear in mind; light roast are denser and got less solubles than dark roasts. So the good taste is not as quickly released as with dark roast.

I know of two strategies to brew light roast:
– Grind finer and pull slow long shots, like 40 seconds instead of the traditional 25 seconds. Or even 1 minute shots on a Slayer espressomachine.
– Grind so it runs faster. And go for brew ratio 1:3 (thats what I do)

To explore this try letting a shot run really long while you taste with a spoon to follow what taste is extracted. At first it is always very sour and sharp. So maybe skip the first 10 seconds that comes out. But then keep tasting along untill it gets weak (=no more taste is extracted). In this way you can tell when the good taste is extracted. In a dark roast it gets weak quicker than with the light roasts.

Here is lots to play around with. I have had great shots of light roast espresso that ran only 18 seconds to achieve the 1:2 brew ratio. And I had a shots where good taste kept coming out even after 60 grams in the cup with 18 grams coffee in the basket.

Dudley Powel from Horsham Coffee Roaster (UK) also found that running faster shots works better with very light roasts. His recipe is:
18g in – 54g out – 26 seconds

Read his whole blogpost at https://www.horshamcoffeeroaster.co.uk/blogs/news/change-your-roast-profile-or-change-your-brew-method

It all also depends on your equipment. Christian Hansen (Denmark) says he goes for brew ratio 1:2 with conical burr grinders but 1:3 for flat burr grinders. Conical burrs gives a more spread out particle distribution.

Making espresso of very dark roasted coffee seems to be best when it runs very slow and runs thick like syrup.

8. Storage
Light roasted coffee often gets better when rested a bit. For a start 4-5 days. And sometimes light roasts first peak at 3 weeks after roast date. If a coffee do not taste good in the first week – try letting it rest for some weeks.

Boris Lee once had an Ethiopian Gesha Village roast that was flavorless at first. He had given up on it but accidentally tried it after 3 months (stored in a sealed bag) – and then it was much better.

The Danish roastery La Cabra roast very light (no more than 1 minute from First Crack start). They say their espresso roast is best between 30 and 60 days.

Dark roasted coffee (roasted to 2nd crack) is best between something like 2 and 10 days. Later the oils will get rancid = taste bad (well, some people don’t notice this). When you roast to Second Crack the oils will come out. If you stop at the beginning of Second Crack the oils may not be visible right away, but will appear as small wet dots on the bean surface. If you roast longer the beans will be completely covered with oils = look wet. When the oils has come out they are more degraded and exposed – and so they quicker go rancid than in lighter roasted coffee.

James normal dark roast

But as always; taste for yourself. This is just guidelines to inspire you. Here are lots to explore.

Color scale

In podcast episode 3 we measure the color of the roast on the Agtron scale.

I just did blind tasting of a Colombia bean roasted to different roast degrees/ color.

95 Light – acidic, sweeter, no smoke

85 Medium light- acidic, sweeter, no smoke, not bitter

75 Medium dark – smoke, toast

65 Dark – high in smoke/tobacco, burnt, very bitter

95 and 85 were more alike and clearly different from 75 and 65.

Calling color change

From green to yellow to fithy shades of brown.

Color change is a good way to follow the roast. It is more solid than bean temperature reading that is influenced by other things than what is going on inside the beans (see sensitivity to airflow).

It is difficult to make establish “Now it’s yellow” and note the time … or “now its the dark brown color where I dump the roast”. The color changes (CC) are gradual and the beans do not change evenly. You just have to find your own way of doing it. Like; when 80% of the beans are no longer green, I call it yellow.

Also – what a color look like depends on the lighting.

Here I have two different lights on my roaster. The photos are taken 10 seconds apart. The first light gave a more yellow color – than the new ligth (the one with a a circle of light around a magnifying glass).

Fil 29-11-2017 16.21.35

Fil 29-11-2017 16.21.19

Read more about Yellow point at  http://coffeenavigated.net/roasting-coffee/#yellow

Listen to podcast episode 3 and 7 where roasters talk about how they use the bean color during the roast http://coffeenavigated.net/podcast-roasting-navigated/


New podcast episode

Episode 8 – published in December 2017

Episode 8 in the podcast Coffee Roasting Navigated is about the many differences on very light roasts  and the darker ones roasted to Second Crack.

Listen here: http://coffeenavigated.net/podcast/episode8roastdegree/

Boenner uens overflade 12sep2016

James normal dark roast

Episode 7 – published in November 2017

Episode 7 in the podcast Coffee Roasting Navigated is with Kaya Caretta. She is roaster at the bean importer Nordic Approach in Norway. This is only sample roasting: each batch is 100 grams and the roaster is a small Probat gas-roaster. It’s very different from roasting 120 kilos as Kaya did in her former roaster job.

Daily she roasts more than 40-60 new coffees – apart from their coffees in stock.

Listen here: http://coffeenavigated.net/podcast/episode-7/

NA Oslo Kaya Therese roaster

Episode 6 – published in October 2017

Episode 6 in the podcast Coffee Roasting Navigated is with four roasters at the Danish Roasting Championship. Again I ask them about how they decide to stop the roast. But we also talk development times and more.

Listen here: http://coffeenavigated.net/podcast/episode-6-four-roasters/

Winner and participants

Episode 5 – published in September 2017

Episode 5 in the podcast Coffee Roasting Navigated is about listening to the beans cracking and counting seconds.

It is a mix of my own background in coffee roasting and roaster Mikkel Selmer from La Cabra.

Listen here: http://coffeenavigated.net/podcast/episode5/


Episode 4 – published in June 2017

Do you go for high acidity or more body in your roast ? How do you roast a Kenya for a light espresso ? And how do you present your beloved coffee for the customers who dont know coffee ?

Episode 4 in the podcast Coffee Roasting Navigated is with Tony Jacobsen from Norway. He own a coffee shop and roastery in Trondheim.

As in episode 2 and 3 – I interview him about how he decides to stop the roast. He goes by bean temperature.

Listen to the interview here: http://coffeenavigated.net/podcast/episode-4/

A brittish Youtube-channel made a review of two Geisha coffees from Jacobsen og Svart: https://www.youtube.com/watch?v=5xyKvXq9G_M

Jacobsen and svart



Bean probe sensitivity to airflow

The bean probe does not only measure the temperature of the beans. It is affected by the metal carcass where it is fixed – and by the air passing by.

The bean probe is quicker affected by the airflow than the beans. Metal absorb heat quicker than the cellulose beans. Think of sitting on a bench in the park on a cold day; the difference of a wood bench and a metal bench. Coffee beans are more like wood than metal.

Here I have tested the bean probes sensitivity to airflow.

This test is on my Bullet R1 roaster (a test roast with old beans, not meant to taste good). The bean probe is a NTC precision type.

Look at the graph after 8 minutes:

Peru test ny probe sept2017

In the last 4 minutes of the roast I jumped between a high airflow; F7 and a low; F2 (and once F1). Each time approximatly 30 seconds stretch. I chose F7 because already at F5 the airflow starts to cool rather than increase heat transfer. That is with 400 grams batches – at larger batches it takes higher fansetting.

High airflow made the ROR go negative within 10 seconds.
Low airflow made it go positive within 10 seconds.

During this shifting airflow the Bean temperature (BT) did anyway rise from 187 to 191°C, measured at low airflow. Probably due to heat transfer from the drum, where the heat setting was constant at P3 during these 4 minutes.

Data excelark

Clearly the bean probe is not only affected by the actual bean temperature – but also of the airflow. As we long expected. And as Rob Hoos also wrote in his Roast Magazine article this month (the sep/oct 2017 issue). He also talks about it in this video https://www.youtube.com/watch?v=IQjxCHE10HQ

Read more about the Bean Temperature under Roasting Basics.

Note: The first 8 minutes of the roast was because I had just changed the bean probe. At first the test was only to see the difference to the old one. But during the roast I got the idea to test the airflow impact on the BT reading.

Different batch sizes

Another indication that airflow is affecting the BT probe … is that the reading at First Crack start depends on batch size.

In general it is established that First Crack (FC) starts around 200ºC. But it is very common that the bean probe on a roaster gives a lower reading. For all types of roasters.

On the Bullet R1 I have seen a range from around 170ºC up to 196ºC for FC start. This is affected by two things: if it’s an old or new probe … and on batch size.

The lower temperature happens when only roasting 400 grams. The Bullet R1 has a capacity of 1 kilo. Below you can see 2 batches Ryan did with the same bean; 700 grams and 1,000 grams.

700 grams:

700g_Ryan Garnes

1000 gram:

1000g_Ryan Garnes

First crack comes higher at 1 kilo:
At 700 gram First Crack sets in at 191ºC.
At 1,000 grams it sets in at 196ºC.

In both cases airflow was around F4. The air moves from the back of the drum – through the beans – and affects the bean probe placed on the front (read about Bean probe sensitivity to airflow). When the air travels through very hot beans it gets heated up before hitting the bean probe. More hot beans will heat up the air more. Therefor higher BT reading at FC.

At yellowing point the 700 grams batch lies higher:
At 700 gram at 149ºC.
At 1,000 grams at 141ºC.

Here the beans are not as hot than at First Crack. So the beans rather cool down the air than heat it.

Coffee grind: The taste of fines

The smallest particles in coffee grind are called “fines”. First fines was said to attribute bitterness and bad flavors to the coffee. Now fines are considered important to make coffee taste great.

How can fines end up giving opposite taste impressions ?

cup-only-22majI have long suspected it had to do with how the fines were situated in the grind: The fines can either stick to larger particles – or to other fines.

Grind untouched

Each result in a different taste: when fines are attached to bigger particles they act as part of the large particle in the extraction and do not over-extract as when they are separate where fines only stick to other fines.

Lately I have done a bunch of experiments on this Read more here.


Kenyans for a light roast

I have been exploring roasting Kenya beans.

Here I have used a high heat start and aimed for a really low ROR at First Crack. This is inspired by Michael de Renouards approach (see High heat post) and Tony Jacobsen (listen to podcast episode 4).

Kenya beans are typical large beans with high density. So they can tolerate high heat – and maybe need more heat to develop the core ?

To achieve the shift from high speed in the beginning to low in the end – you have to turn the heat down well in advance of the first crack (FC).

I just roasted two batches of Kenya like this. Both roasts hit first crack around 7 minutes. Both have a Maillard phase around 3,5 minutes (from yellow to FC start).

The first one, 400 grams, has higher speed (e.g. ROR) going into FC.
DT (development time) was 48 sek and it rose 2,7 C.
Thats an avarage ROR on 3,4 during DT.

Kiambara nr1 25juni

Number 2, 500 grams, has a lower speed/ROR.
DT was 1:49 min and it rose 1,7 C.
That gives an avg ROR at only 0,7 !

Kiambara nr2 25juni

I was afraid ROR at 0,7 degrees pr minute was too low. But no, this was the best roast. A really elegant acidity. A nice body. Much more interesting than number 1.


I cupped them after only 2 days after roasting. Thats early in my world. But I had to ship off the 500 grams batch to a friend. So I just wanted to check if it was acceptable. Normally with Kenyans I let them rest a couple of weeks before opening.

Roasting in changing weather conditions

It is well known that the weather makes a difference to the roasting process. The change of seasons. A clear sunny day versus rainy weather.


At first you should think that the temperature was the only factor. But  more factors play a role – like humidity.

And each factor may influence different parts of the roasting proces. So it’s complex. And it easily gets confusing. It also depends on the type of roaster and ventilation.

I will not claim that I got hold of all factors affecting your roasting. But here I can mention some of the factors:


At first you should think that the temperature was the only factor. If the surroundings are colder and the air sucked into the roaster during it takes more energy to heat up your beans

Also, what temperature do your beans have before roasting ? Does your bean storage change in temperature ?

Bean storage temperature
If your beans are 25°C and you heat them up to 200°C in 8-9 minutes, that is an average of 20°C per minute. If your beans instead is only 5°C, then there is a 20°C more “road” to heat up till 200°C – so that will take an extra minute to reach.

But temperature is not the only factor – the humidity also affects the roast.



The roaster sucks in air from the outside during the roast. Even though you are roasting indoors the humidity / H2O content in the room is significantly affected by the weather outside.

The level of humidity in the air can work in two ways:

(1) If the air is already heated humid air will transfer heat quicker than dry air. Water molecules transfer heat more efficiently than other air molecules, which are mainly Nitrogen and Oxygen.

So, if you have any airflow in your roaster: Air with higher water content will transfer heat quicker.

Have you tried being in a sauna compared with a steam bath (also called Turkish Hamam) ? The steam bath is about 40°C, but the sauna is like 80-90°C. That’s because the heat in humid steam bath air will hit you much more efficiently than the dry sauna air.

(2) The roaster sucks in air from the outside during the roast. If the air is not heated up before entering the roasting chamber the humidity will compete with the beans for the heat. So; dry air will make a quicker roast than humid air.

It might also be a factor that drier air gives quicker drying of the beans because it removes water quicker from the beans.


Relative and Absolute humidity

But the air on a rainy day in summer doesn’t have the same water content as a rainy day in the winter.

Lets compare a humid day at 1°C and at 25°C.

Moisture meter shThe humidity is measured with a moisture meter also called a hygrometer. But it will only give the relative humidity.

Relative humidity is the amount of moisture in the air compared to what the air can “hold” at that temperature.


As you see on the graph below; warmer air can hold more water than colder. The x-axis is the temperature in Celsius. The y-axis on the left is grams of water per cubic meters (m3). The lines are levels of relative humidity.

Rel vs abs humindity

When outside air is sucked into the roaster we need to know the absolute amount of water per volume air.

Lets look at high humidity, 100% (rainy weather):
At 25°C the air holds 23 grams water per m3
At 1°C the air only holds 5 grams per m3

So if its 25°C outside and 100% humidity, there will be 4,5 times more water in the air sucked into the roaster – compared to 100% at 1°C.

As you can see on the graph, the difference in water content is much bigger at 25°C than around freezing point. So, in warm weather changes in humidity makes a bigger difference: At 25°C a dry day with 30% humidity has 7 grams water … compared to a humid day at 90% has 21 grams of water.

You can see this on a cold glass of water. On a warm humid day quickly water will condense on the outside of the glass. Thats because the warm air contains a lot of water. But right by the cold glass, it gets cooled down and the reach “dew point” – and condense from water vapor into fluid water.

Dry or humid climate
From the graph you can also see that this has biggest impact at higher humidity. Here in Denmark we got high humidity (often above 80%). But if you live in a low humidity climate (like in the desert), look at the 10% curve on graph: the water content doesn’t change much at different temperatures.


Calculate your absolute humidity
If you want to observe this in relation with your roasting – you can either have a moisture meter in the room, close together with a thermometer … Or get data from an official weather station nearby.

And then calculate the absolute humidity – like with this one http://planetcalc.com/2167/
It also takes in Barometric pressure, but it doesn’t have a big influence.

Note: If you use your own moisture meter – good calibration is needed. Moisture meters can easily be 15% wrong.


PRactical experience

How big the influence is depend on how much airflow you use. And remember the coffee beans also loose water during roasting; going from a water content of around 10% to around 2 %.

Experiencing HIGHER humidity making heating during the roasting process more efficient:

Roaster Morten Riiskjær roast 150 tons of coffee a year, both on a 12 kilo Probat roaster using gas – and on a 60 kilo automatic roaster (listen to him roasting by smell in the podcast from december 2016).
He says: “When the weather is both warm and humid – you really have to watch out because the roast quickly runs out of hand”. So he uses lower charge temperature and lower heat around First Crack.

Experiencing LOWER humidity making heating during the roasting process more efficient:

Bob Werby had been roasting a lot on his 1 kilo Bullet R1 for a year – when he changed the humidity levels in his house. Going from 60-65% rel humidity to under 50% using dehumidification Equipment.

This made the roasts quicker. With same settings and batch size he reached first crack at around 7:15 minutes at 47% humidity – compared to an average of 8:50 min to first crack with humidity levels above 60%.


If you would like to explore this in details join the humidity project http://coffeenavigated.net/humidity-project/

Atmospheric Pressure

A roaster told me about this impact on the roasting process:

A fan typically controls the airflow in a coffee roaster. The fan has speed settings. However, the amount of air that the fan moves does not only depend on the fan speed setting, but also depend on the backpressure from the rest of the flow path. So if you have a chaff filter or collector depleted with chaffs it gives more resistance to the fan and the airflow is lower.

And … if the outside air is denser (higher barometric pressure, higher water content) it gives more resistance to the fan and the airflow is lower.

I suppose how much the weather affects the airflow in your roaster  depends on extent of airflow: If you roast with a low airflow it wont affect as much.


More factors

In general, lower water content in the air gives quicker drying … This should give a faster roast … But the question is if it has any significant importance ?

And roasters living in high altitudes say that affects the roasting too.

Somebody said that the gas burner is affected by weather conditions.

…. So many things influence the roasting process

High heat start

Our roasting community here in Denmark is exploring a new approach on the Bullet R1 roaster.

15 of us were on a roasting course with Michael de Renouard from The Factory Roast Lab Copenhagen. He is a roasting consultant and travels the world teaching coffee roasting. In his own roastery he is roasting on a Loring. He roast quite light.

Refshaleoen kursus maj2017

Michael tried out the Bullet roaster. He thought it did well; no burned or smoked taste in the beans. And its possible to get the beans heated quickly. He likes that you can control heat and airflow separately.

He found that you could start out with high heat without the beans got scorched/burned. Preheat 200°C for a 700 grams batch and then P8 – leaving room to step up to P9 at then end of the ROR peak.

But this was for high density beans (high grown). Be aware that lower density beans, like brasil, need a lower preheat temperature. Steffen got a Costa Rica bean which gets burned if the preheat is more than 170°C.

The high heat makes a fast start on the roast. But if it doesn’t scorch the beans, then no problem. Michael focus on the lenght of the phase from yellow until First Crack start. Here he aims at 3 minutes and at the same time aim to bring ROR below 5 for the First Crack phase. To do this the heat must be turned down markedly.


Exploring the difference

Here Thomas Villars used the strategy on a etiopean bean. He thought it tasted better than earlier roasts of the same bean. Despite FC starts as early as 5:23 min.

New strategy:

Villars Homa rist 13majIn general a fast roast like this gives more “clarity” in the taste – and less body. Here the “middle phase” – from yellow to FC start – is 2:15 minutes long. It should give more body to prolong this phase.

Earlier Thomas roasted the same bean like this:

Villars Homa 30apr

Update 2 months later:
Thomas has continued this new strategy. He like his coffees better now.


There are many approaches in coffee roasting. Don’t take this website as the only way to do it. Just take it as inspiration – and explore for your self what suits your taste.

Repeating a roast profile

If you made a good roast, you likely want to repeat it :-) But thats not easy to do accurately because so much influence a roast.

Steffen from KaffeRist do it often. Here he made 7 repeated roast of the same bean – trying to make the same roast profile. All done in a row.

You can see how the curves doesn’t overlay completely. And First Crack (FC) starts at different times and temperatures.

Steffens 7 gentagne rist april2017

He roast on a Bullet R1 roaster. The software got a PlayBack function that repeats the settings of preheat, power and fan during from the roast you want to repeat.

But the same settings doesn’t give the same profile even though it’s the same bean and the same batch size. So during the roast Steffen overrules the automatic settings. The ROR curve is the best way to see where the Bean temperature (BT) is heading – to adjust in time.

And then he listens for the First Crack (FC) start every time. And aim to make the development from FC start the same every time: regarding time and temperature rise.

Roast by color

My podcast Coffee Roasting Navigated is about the different approaches in coffee roasting. We start by exploring the different ways to decide how to stop the roast.

In Episode 3 it is about roasting to a certain color. We are at a roasting course with Morten Münchow from CoffeeMind. I have called the episode “Roasting by color” but Morten focuses on more than the bean color to make a good roast.

Listen at http://coffeenavigated.net/podcast/episode-3-roasting-by-color

In Episode 7 roaster Kaya Caretta tell about looking at the color during the roast. Listen at http://coffeenavigated.net/podcast/episode-7/

Fil 12-12-2016 10.14.41Color change during the roast – samples taken out each minute of the roast.

Fil 10-02-2017 09.51.15Roasting class with Morten Münchow (on the right) from CoffeeMind.

Fil 10-02-2017 09.52.47Color and Agtron measurements of different batches.
Here you can see that #6 is darker than #5 – which is reflected in the Agtron values: #6 was 75 and #5 was 84.


Roasting by smell

How do you decide when to stop the roast ? Once, I asked roaster Morten Riiskjær this question. He said by smell. The smell of onion has to be over before stopping.

He has been roasting coffee for 7 years. I visited him in the roastery to try to pick up what he could smell during a roast. He also looks at the bean surface.

Hear Morten talk about it in episode 2 in the podcast Coffee Roasting Navigated http://coffeenavigated.net/podcast/2-roasting-by-smell/

And here a video with an american roaster who also use the smell during First Crack, Eliza from Mill City Roasters:


Morten and his roaster – on the day we recorded for episode 2:








When do First Crack start ?

The onset of First Crack (FC / 1st crack) is an important control point in the roast of coffee. Rapid development takes place in the taste from here on. First crack is when the beans expand and make a noice like the crack of a thin branch.

But all the beans do not crack right at the same time. First one, then quiet, then another. But at some points lots are cracking. So when should you call the time ? Was it a 9:15 or 9:40 minutes ?

Another thing that makes it difficult is the background noice: the noice of the roaster and the beans hitting the drum. So its difficult to hear the cracks.

Try listen to this sound bite … Make you own notes before reading on


I have made podcast episode about this. It is episode 5 in the podcast Coffee Roasting Navigated


Some beans have a more clear FC start than others. A late FC (like more than 13 minutes) will tend to make a weaker crack. Low density beans tend to make weaker crack.



I asked in a roaster group on Facebook (click on the picture to see a bigger size):


Around 0:15 into the sound bite, I also was thinking: “is it starting now ?” But then it silenced, so No.

Then there is one clear snap around 0:55. But I need more of a roll of cracks to say that it has started.

So I would also say around 1 minute.

When you can’t hear the cracking

How well you can hear the cracking is different from roaster to roaster. Some roasters are so insulated that it is impossible to hear.

This is what I hear roasters then do:

-> smell the beans in the trier. At first crack comes a smell of vinegar.

-> look at the beans in the trier. When they crack they jump around.

Listening devices

You can also use some listening device to get the sound. On this photo I listen with a stethoscope. It only really works through air – and not on metal or glass window (because that will transmit all the other noices as well) . On this roaster I took out the trier and fittet the stethoscope on.

Photo by Morten Münchow, CoffeeMind.fil-07-12-2016-11-38-35


Here is another device: earmuffs with a tube. This photo is from the roastery Holy Bean in Denmark. Bo Nielsen got them from CoffeeTools.

Fil 08-09-2017 10.32.02



Sound analysis

Research has been done on the sounds during coffee roasting by P.S. Wilson. In his article “Coffee roasting acoustics” he concludes:

> Near the end of the roasting process, sounds known as first crack exhibit a higher acoustic amplitude than sounds emitted later, known as second crack. First crack emits more low frequency energy than second crack.

Link to article: http://asa.scitation.org/doi/full/10.1121/1.4874355

But I hear that the problem is to get microphones that can withstand the heat from the roasting process.


Taste preferences

When you get advice from other roasters … it’s important to know their taste preference.

What roast degree do they prefer ? Do they prefer clairity or a richer taste ? What kind of aromas ? How much acidity ? and so on.

itunes-logo1We do not like the same things in coffee. But also; we don’t notice the same things. So much is going on in the taste of coffee – so we can easily get different experiences from the same coffee.

Some people immediately notice bitterness. If the coffee has any bitterness they don’t like it. Maybe they like a light roast with clairity and fruit/flowers aromas. And dislike the burnt flavours.

Others only like coffee with solid burnt flavours, but really don’t pay attention to bitterness. That’s in the darker roast range. They find the light roast thin and missing what good coffee should taste like.


This is Henrik and me (Therese). He loves very dark roasted coffee – like in the Italian coffee tradition.

I find it tastes like a car workshop and awfully burnt. I don’t like it.


Read more about roast degree in the Coffee Lanscape and Light versus Dark.

Normally I roast quite light (from 45 sec to 2 minutes from 1st crack start). But I am not at the lightest end of the scale. Coffee roasters like The Coffee Collective here in Denmark and Tim Wendelboe in Norway are a bit lighter than me – and they like more acidity.

la-cabra-2George Stavrinou from Australia has the same roaster as I (a Bullet R1). He asked me what I was trying to achieve with my roast profiles regarding to taste.

My taste preference in coffee
1) Avoiding bad taste
2) Balanced in the basic tastes. No strong acidity, bitterness or sweetness. A little is fine. It should be pleasant in the mouth.
3) A big aroma. In a light roast I get a certain kind of grand aroma that I can’t associate with a specific food/flower/whatever. I like deep aromas that stays as a pleasant aftertaste for a long time.
4) Taste the characteristics of the bean.


riste-farveskift-ida-kofodPhoto by Ida Kofod from Kontra Coffee.

She took out a sample each minut during a 14 minute roast – to show the color change.

Good and bad tasting of the same bean

If you really want to learn how different roasting profiles affect the taste – then roast 2 batches on the same day with only small differences in the profile. And then taste them side by side in the weeks afterwards.


Here is an example of a good tasting and bad tasting coffee of the same bean. Much in the roast profile are alike, but not all the way. What causes the difference in taste ?

The bean is a washed arabica from Uganda. Fairly high grown at the Mount Elgon mountain on the border to Kenya.

The good tasting, 400 grams, by Therese

mt-elgon-great-2016-11-21-05-29-00Taste: no burn flavour, no bitternes, nice round and big aroma.

I roasted it again 9 days later. First the curves were very close. But after 5,5 minutes the ROR levels differed. Here both curves:

Two roast of the same bean Mt Elgon nov2016

The higher ROR level here gave an earlier FC; at 7 minutes in the second roast where as the first had 8:45 min.


This coffee didn’t taste good to me. It had bitterness and burned taste. And a weak aroma = boring coffee.


What could be causing this difference in taste ?

First the alike elements
The development-% was around 24% for both (the time after FC related to total roast time). And weightloss was about the same: 14,3 and 14,5%

Development time (DT) was 2:44 minutes for the good one. The bad with more burned taste you would expect to be roasted longer, but no, its roasted a bit shorter: the DT was only 2:19 minutes.


Possible explanations for the burnt taste
I cant say for sure why they tasted like they did – because several things was different. But here are some thoughts:

(1) A higher temperature rise in the bad one: 12°Celcius (and BT ended on 181°C) … where as the good one only rose 6-8°C (to end-BT at 175°C).

(2) When entering First Crack the bad one had a ROR around 10°C pr min. Whereas the good one was around 5. I have heard a recommandation around 5°C per minute – and not as high as 10°C when entering FC and for the rest of the roast.

(3) The american roaster Rob Hoos talks about the importance of the middle phase: from yellow point to FC start (see his book “Modulating the flavor profile of coffee“). He calls it the Maillard phase. In these two roasts the drying phase up untill yellow point are not that far apart: 4:00 and 3:45. But the lenght of this middle phase is 3 minutes for the bad one, and 5 minutes for the good one.

A roast consultant told me he prefers 3 minutes, so thats not criminal in itself. But maybe it suits this particular bean better with a slower roast; a longer middle phase and lower ROR levels during FC.

(4) They flavours go up and down during the roast – so maybe the bad one here would have been better if dropped earlier or later at than 2:19 minutes from FC start.


Martin Kjeldsen roast of the same bean

Martin Kjeldsen lives in different part of Denmark, but we got the same bean – and the same roaster, the Bullet. The bean is from Uganda from Mount Elgon (on the border to Kenya).

Martin have also roasted the bean several times. This is his best tasting batch:

500 grams, preheat 185°C


Martins bacth was roasted 2 minutes from FC start to end-BT at 192°C. My good one was roasted 2:45 min and to BT 175°C. But our bean probes do not measure alike. Notice the difference in FC starts: Martin at 182°C. Mine at 167°C and 169°C.


Read more under Roast profiles.

Adjusting profile by control points

beans-trier-sh1The current roast doesn’t necessarily respond the same way to power and fan settings as a previous roast. And the roasting proces is slow to respond on changes so you have to make changes in advance – its like sailing a ship.

So I wanted to find control points along the roast that tells me where the roast is headed – so I can adjust the heat in time. Me = Therese.

I first wrote about adjusting by control points in November 2016. Since I have continued to develop my strategy.


Update October 2017
After having been focusing for a year on the bean temperature profile and ROR – I have now moved it to a secondary position. Because it didn’t really help me make good coffee. And because what happens in the bean probe is not exactly the same as what happens in the beans, see Bean probe sensitivity.

But I still use the BT and ROR as input to how I manage the roast.

In the beginning of the roast I look at these parameters to see how quick the roast got started:

Temperature of turning point (TP)
The ROR peak level
Time when bean temperature (BT) reaches 115 C.

If the roast is going too slow for what I want → I will use more heat (P). If it goes too fast → I will use less heat.

What happens in the beginning of the roast very much determines the direction of the rest of the roast – and more so the larger the batch is. It is very difficult to change direction later on.

From there on I note the physical change: color and start of First Crack.

Time of yellow point – and note temp and ROR
Time of medium brown – and note temp and ROR
Time of start dark brown – and note temp and ROR
Time of First Crack start – and note temp and ROR

I have in mind approximately how fast I want to reach First Crack, the length of the middle phase (=from yellow to first crack, MAI) and the ROR level around first crack. I adjust the heat according to how the roast is progressing and how I know the roast behave in the different stages.

To stop the roast I go by time: counting seconds from first crack start.

I don’t worry about getting the exact same BT and ROR curves as an earlier good roast of the same bean. I don’t worry about have a perfectly nice declining ROR curve.


My earlier approach:

Post from November 2016

I have found a new approach to decide adjusting power and fan during the roast on the Bullet R1. Until now I have just tried to do what worked earlier. And then hoping it was right for the current roast.

When it didn’t work out, it was too late to do anything about it. Like a ship the roast takes time to change direction.

How the batch develops from a given setting is much affected by type of bean, batch size, ambient temperature, how clean the filter is and so on.

My hopes for this roaster were to be able to design the profile: ROR levels, time of 1st crack (FC), yellowing and so on … And to know what I am doing during the roast. Not having to repeat the same roast many times before I get to where I want.


So I got the idea to find control points that tells me where the roast is headed. So I can adjust the heat in time.

When the roast has reached BT= 115 C at a certain time, I know if its on time or ahead or behind – and I can adjust the heat to regulate.

ROR levels are the speed of the roast and predict the time to reach FC start and so on.

I analyzed a bunch of my previous roasts. Both the successful ones and the unsuccessful (acording to how I want to roast).
Successful ones = when FC start around 7-8 minutes
Unsuccessful = FC starts later than 10,5 minutes

I picked milestones along the roast: bean temperature and yellowing and FC. Then noted the time and ROR.


There was a clear pattern. The unsuccessful roasts had lower ROR, naturally. Not so clear at 115 C. But from 130 C and onwards.

With this list I then roasted 3 batches. What a difference it made! Now I had the feeling of knowing where I was headed and could adjust heating in time.

All 3 batches got a FC on 8-9 minutes. I got the ROR levels more where I wanted them.

I am thrilled :-D

I have posted my list under Roast Profiles. But its only a start. Surely it will be developed as I go.

Be aware: Our bean probes are different: so you can’t use my list if your FC onset isn’t around 170 C. Make your own list.


My strategy has developed since I started my control point guide in November 2016, see http://coffeenavigated.net/roast-by-control-points/

This is for high-density beans = high grown (I haven’t investigated the threshold for this, but something like above 1.500 meters) and a light roast.

My bean probe may be different than yours, so you cant use the degrees directly – but this can serve for inspiration to make your own guidelines.

New strategy

A high heat start → higher preheat than earlier

To prevent to big a drop in ROR after the initial peak (at somewhere around 1-3 minutes), increase heat at this point

Already at 150°C; aim for ROR level around 3-5 at FC start (typical around 170°C with my bean probe) by slowly decreasing Power

Preheat for 400 grams: 185°C – but if its the first batch 190°C

Start at P6. At turning point go to P7. During the ROR peak rise to P8. Exactly how this is done depends on Turning point temperature, the ROR-level of the peak and the time for reaching 115°C and 125°C

Fan at P2 until yellowing point or just as browning starts then F3.

After yellowing point, around 150°C decrease power step by step. I adjust this according to:

Aim for ROR around 10 at 150°C . And at 160°C ROR at 8 and power stepped down to P4.

At First Crack start have power at P2 and have ROR around 5. During FC the ROR has a tendency to drop. Don’t worry too much about it. But try and keep ROR between 2 and 4. If ROR is to high try with fan at F5 or even F6.

If ROR is higher than 5 after FC start, then do a shorter time to drop.

 400 grams ethiopean (Homa)

Homa 25juni

ProfileTool for the Bullet roast data

Another of the Danish Bullet owner; Steen Hjelmstrand – has made this software to do more things with data from the Bullet roaster, than the RoastTime software from Aillio.

Steen have name it ProfileTool and you can download it for free from his website http://www.hjelmstrand.dk/profiletool/

Note: keep an eye for updates. Steen is continuosly developing the software.