Grinder alignment

Get the best tasting coffee from your grinder

Exactly how much side by side the two burrs are placed in the grinder has importance for the particle distribution of the coffee grind. This is called burr alignment.

Such difference in particle distribution was measured in a project done by Christopher Hendon, Matt Perger and more, see https://baristahustle.com/grinder-paper-explained/ This graph is from Supporting Information. The blue curve is good alignement of the burrs with. They grey curve is bad aligned burrs:

forskel-pa%cc%8a-alignementWarning: Trying to align your grinder may drive you nuts 😉 Most grinders are not build to get adjusted in the alignment. A few new ones are, but they are crazy expensive. So if your grinder doesn’t really got a problem – don’t touch it.

 

What does it matter for the taste ?

The more alike coffee particles are in size, the more clear taste and aroma.

The more difference in particle size, the more both over- and under-extracted coffee (mix of bitterness, bad flavours, sour).

Where as fines is another story – see The taste of fines.

How can you tell bad alignement ?

By taste

Good alignment makes the aroma characteristics of the coffee stand out more clear

By sound

Matt Perger did this sound diagnosing of burr alignment of the EK43 grinder
https://www.youtube.com/watch?v=_jWlpz9mELM

Here you can hear the chirping sound of burrs touching with a Mazzer Super Jolly grinder https://youtu.be/xrNYzvXq8i0 First only by ajusting to zero. Later by pressing the adjustment collar on one side. Thats how sensitive the burrs are.

Waveforms
The waveforms from the sound of chirping on a grinder looks like this. Jon have recorded the sound of his own Ditting grinder – and compared it to the recordings from Matt Pergers video with the 4 states of EK43 alignment:

Jons lydanalyse m forklaring

Bad aligned burrs will touch once pr rotation – this makes a clear single peak in the waveform. More peaks pr rotation indicates a better alignment, as more peaks indicates more contact between the burrs through the rotation.

Ideal aligned burrs would touch the entire rotation, making very long series of equal sized peaks pr rotaion.

 

By how it looks when brewing

When making a filter brew you adjust the grind size according to the time it takes for the water to pass. Some aim at 2:20 minutes, others at 3-4 minutes. If the water takes too long to drain through, then grind coarser. Too quick then grind finer.

fil-06-10-2016-18-58-47This photo is a V60 brew from a bad aligned grinder:
1) a little coarse grind is left high in the filter (called “high & dry”)

2) the drain slowed down, when still 1-2 cm water stood above the grind in the filter. Very little coffee dripped through = too many fine particles clogging the filter.

So this grind had both too big particles (= boulders) and too many fine particles = typical for bad alignment of the burrs.

 

How to do alignment of your grinder

For Mythos One – can be used for other grinders

Matt North have made this great guide to alignment of the Mythos One grinder  Here is used the whiteboard-marker method.

Lido handgrinder from Orphan Espresso

Lido 2: https://www.youtube.com/watch?v=npVWLJnBcAs
combined with this http://coffee.stackexchange.com/questions/2515/how-to-fix-burr-contact-alignment-issues-on-an-oe-lido-hand-grinder-on-fine-grin/2516#2516
Extra: when you have aligned the burrs at fine setting, then go back to normal grind size and grind a handful. This will slightly push the burrs. Then test again at fine setting if the burrs touches.

Lido 1: https://www.youtube.com/watch?v=ok4IQvrTSD4&feature=youtu.be

Flat-burr grinders

When aligning flat-burr grinders we normally use thin pieces of metal foil to align the burrs – but before using metal foil, another method is to start by mounting the burrs in the different positions, just by rotating the burrs. The burrs themselves should in theory have no differences in height around the burr, but in reality, very small differences can occur.

Do not switch the lower burr with the upper burr. The lower burr should always remain the lower and vice verca – this alignment is about rotating the burrs individually to different mounting posistions.

If your burrs has screwholes, rotate the burrs individually to the different screwhole/burr combinations to check if some combinations are better aligned than others. If your burrs has no screwholes, simply rotate the burrs individually to different positions to check if some positions has better alignment than others.

EK43

Matt Perger: https://www.youtube.com/watch?v=5-cf0Iack5Q

Good tips when dismantling the EK43: http://grindscience.com/2017/07/my-ek43-tips-and-tricks/

Note: how much the front screws is tighten also affects the alignment https://www.youtube.com/watch?v=V02UBGeLSx8&feature=youtu.be

A third point that affects the alignment:
https://www.youtube.com/watch?v=r0RjPFi-Uzg

Socratic Coffee made this analasis of Ek43 grind from before and after alignment
https://www.instagram.com/p/BVpA-vMj8YF/

 

Alignment tool Frank DurraTitus grinding just launched this alignment tool to measure the inner burr, here in May 2017.

Frank Durra describes the purpose like this:
“It aligns / measures at the roots of the problem which is the axial alignment of the inner burr due to irregularities of the aluminum case”

 

Alignment is more important with bigger burrs

 

Alignment and burr size