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).

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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/

 

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:
https://www.youtube.com/watch?v=zSVLVwQUacc&feature=push-lbss&attr_tag=g2vFzL_dTGaDiUJa-6

 

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

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