Your coffee roaster will pour his heart and soul into getting your beans perfect, fresh and delivered as quick as possible. What you do with that product to get the best coffee for your customers (or at home) is extremely important.
It starts with your grinder. And yes, grind size matter!
The backbone of great coffee is the perfect ground.
For those who want excellent coffee - see our number 1 tip to help improve your coffee. Small adjustments give big results!
Let us get to the bottom of this - your grind size is crucial and differs with each brewing method.
Grind size does not determine how strong your coffee will be!
Yes, I have to say that again... Grind size does not determine the strength of your coffee. It is true that a finer grind will have a bigger extraction, ie more soluble particles dissolved in the water. This will affect the taste more than anything else.
You get stronger coffee by increasing the coffee to water ratio. For stronger coffee, add more beans.
Why grind size influence coffee taste?
Imagine a bucket of water where the bottom is punctured with holes. Now fill that bucket with medium rocks; this represents coarse coffee granules, when you pour water over the stones it runs over them and spills out the bottom. Now fill that same bucket with sand and the water will slowly sip through it and drip out at the bottom. As hot water pass over the coffee grounds it is dissolving soluble flavors in the water which is the extraction process, too coarse coffee makes it weak and under-extracted, very fine coffee makes it bitter and over-extracted.
Another reason for extraction is the surface area in contact with water. Extremely fine coffee will cause an over-extraction while too course will cause an under-extraction.
How to adjust your grind?
The most influential factors to determine your grind size is number 1, the time the coffee will be in contact with the water, and number 2, the pressure exerted while doing the extraction.
When the coffee grounds is in the water for a long time, such in the case of a French press (slow brew), you use a coarser ground - more of the surface of the granules is exposed for longer to the water. In an Espresso machine the water is exposed to the ground coffee for a maximum of 30 seconds, and you want the granules to be fine - the surface area are smaller and the exposure to water is shorter.
See our tips below:
Set your grind size according to the "BRU-ing" method you will use to make the coffee!
The flavour and the quality of the cup will be directly influenced by the coarseness of your ground. The grind size influence the interaction with water during the extraction, due to the surface area that will change with different courseness settings. Therefore, do not only consider changing your extraction time, which also influences the flavour of the coffee, but change the coarseness first.
As a rule of thumb - the fresher the coffee you buy the better the taste. This is due to the fact that you can grind fresh beans finer, without causing extraction of the bland compounds. See our notes on Why your coffee should indicate a roast date?
Most beans should result in a satisfactory cup, independent of your brewing method, by adjusting grind size. For example, a good espresso bean can be used for a plunger in the morning, by grinding the beans course for the increased extraction time.
Below is our basic reference guide to get you started.
Extraction time is around 50 seconds and your coffee granules size should be about the size of table salt.
Extraction time is around 3-4 minutes and your coffee granules size should be about double the size of sugar. Taste and residue in the cup (there must be some for plunger) will determine how you should adjust the coarseness.
Espresso Coffee Machine
Extraction time is around 25 seconds and your coffee granules size should be about the size of castor sugar or fine table salt. With the pressure set at 9 bar, and the correct amount of ground, you can adjust coarseness to fix your time.
GRIND SIZE BREW METHOD
Extra coarse Cold Brew Coffee, Camp Coffee Pot,
Coarse French press, percolator, coffee cupping
Medium-coarse Chemex, clever dripper, cafe solo brewer
Medium Cone shaped pour over brewers, flat bottom drip machines,
siphon coffee, Aeropress (with 3+ minute brew time)
Medium-fine. Cone shaped pour over brewers, Aeropress
(with 2-3 minute brew time)
Fine Espresso, Moka pot, Aeropress (with 1 minute brew time)
Extra Fine Turkish coffee
Do not be scared to experiment! Get out your grinder and grab your favourite beans to do a few tastings by varying the grind. You will be amazed at how your taste buds will improve!
See more about this topic by reading this article from Homegrounds to get the most out of your grinder: