In this article, I will talk about grinding, a very important topic when preparing coffee but often underestimated. We all know that roasted coffee comes to us in beans, and we must grind it to make an infusion and thus drink it. Where we do it, and the size of the grind that we obtain will be very important for the preparation.
Many times all the importance is given to the coffee maker, but if we do not have a good grinder, even if we have the best coffee maker, we will never be able to prepare a good coffee. I have already mentioned this in other articles, but I want to discuss the grind you will need for each method and how this affects the final cup.
How is the grind adjusted in the burr grinders?
In the burr grinders, we will find different grinding adjustment systems. In the manual ones, it is by clicks, and in the electric ones by numbers. The lower the number selected, the finer the grind.
The following image shows how the grind is adjusted in both manual and electric grinders:
Does the quality of the grinder influence the grind?
The best quality grinders offer a much more homogeneous grind; that is to say, the pieces of ground coffee beans are very similar in size. On the other hand, lower-quality grinders will produce pieces of different sizes, some finer and others larger, which will negatively affect the flavor of the coffee.
Type of grind for manual pour-over drip methods
In drip methods with manual pour-over, it is easier to identify how the grind influences the preparation.
If we place a coffee with a very coarse grind, the water will pass through quickly since it does not have much resistance. And since it has so little contact time with the coffee, it cannot extract it completely.
This results in a very watery, sour, and tasteless coffee. This will be amplified the coarser you have made the grind. To solve this problem, you should progressively grind finer until you find the right size.
If we place a coffee with a very fine grind, the water will have a lot of resistance and will not be able to pass easily so the contact time will be too long, and the coffee will be over-extracted. It will be very bitter, astringent, strong, and unpleasant.
The coarser you grind the coffee, the more you will continue to notice this astringency and bitterness, but if you grind it progressively coarser, there comes the point when it suddenly disappears. Afterward, you will notice a super-balanced coffee at the right point of sweetness, acidity, and a lot of flavor for your coffee.
The image above shows the effect of a coarse grind versus a fine grind using a Hario V60. With this method, the difficulty of the water passing through the coffee can be appreciated very well, but this also applies to all manual pouring methods (Chemex, Kalita, etc.) and the Moka and espresso machines.
Related: Use of an electric drip coffee maker.
Type of grinding for the immersion methods
In the immersion methods, the contact time between the water and the coffee is determined by us. The finer the grind is, and when it comes into immediate contact with the water, it will be very difficult for the water to penetrate the coffee pieces and extract them, so the contact should be for a short period.
And the coarser the grind is, the more time the water will need to penetrate these pieces and extract all the flavors of the coffee.
How to know which grind to use at any given moment
The same grind setting for different coffees will have very different results because there are different types of beans with different sizes and densities.
In addition, the conditions of the environment where the coffee is ground, such as humidity, will cause the grind to change. For your reference, the grind is classified by the size of the ground coffee obtained and can be fine, medium, or coarse.
The only way to find the ideal grind is by testing. You should grind finer and finer until you reach that point of change where you notice that bitterness and astringency, once at that point, you make a change towards coarser, and there you have found the ideal grind.
When you buy coffee in the supermarket, it usually comes already ground, but we do not know in what form. The package usually says that you can use it for all methods, so it is neither credible nor recommended.
Does the cleanliness of the grinder affect the grinding?
One last aspect to consider, which has nothing to do with the grind itself but can cloud perception if you do not pay attention, is the grinder’s cleanliness and the coffee maker. This is essential to taste coffee at its maximum potential.
You must regularly clean your coffee brewing equipment to obtain the highest quality coffee. Any leftovers from previous extractions can affect the actual coffee and change its flavor.
Related: The importance of tamping coffee. Does it even matter?