How to Read Coffee Grinder Settings? How to Adjust Coffee Grind? How to Brew Espresso with Coffee Machine

How to Read Coffee Grinder Settings? How to Adjust Coffee Bean Grind Size? How to Brew Espresso with a Coffee Machine? What Are the Types of Coffee Grinding?

Coffee beans need to be freshly ground to fully appreciate their rich aroma, which demonstrates the importance of grinding for coffee beans. When grinding, many people have a misconception about which setting to choose. Typically, larger numbers indicate coarser grind, while smaller numbers indicate finer grind. However, each coffee grinder's assembly, transportation, and maintenance are different, so even with grinders of the same brand and model, the same setting will produce two different particle sizes.

Coffee grind size is a challenge that everyone must overcome. According to FrontStreet Coffee's experience answering questions from so many friends, basically more than half of poor brewing results are due to issues with grind size.

Why Coffee Needs to Be Ground

Friends who haven't learned much about coffee might have their concept of coffee停留在 instant coffee, but coffee available in cafes today is basically brewed from freshly roasted coffee beans that have been ground, and it contains grounds. Coffee needs to be ground into powder before brewing because this releases coffee compounds much faster than brewing whole beans. The finer the grind, the larger the surface area of the coffee particles, and the faster the coffee compounds are released.

How Coarse? How Fine?

As mentioned before, pour-over coffee is a filtration extraction method. If the coffee is ground too finely, the coffee grounds will block water flow. On one hand, fine grinding releases compounds more easily; on the other hand, water flows more slowly, extending the brewing time. This can lead to over-extraction, resulting in heavier flavors, stronger bitterness, increased acidity, and potential astringency.

However, if ground too coarsely, the gaps between coffee grounds become larger. On one hand, coarser grinding releases compounds more slowly; on the other hand, water flows more quickly. This can lead to coffee with lighter body, weaker bitterness, reduced acidity, fewer off-flavors, and a cleaner taste. Therefore, an appropriate grind size for pour-over coffee must balance both particle size and water flow rate. Generally, extraction time for 1-2 servings of pour-over coffee should be controlled around 2 minutes.

According to the SCA cupping grind size calibration standard (cupping requires 70-75% pass-through rate on a #20 sieve), pour-over grinding needs to be finer than cupping grind size, so the pour-over grind size should have a 75-80% pass-through rate on a #20 sieve. This grind setting can be roughly understood as what many coffee shops call "fine pour-over grind."

The #20 sieve calibration has one drawback: it can only distinguish between coffee particles larger than 0.85mm and smaller than 0.85mm, but cannot identify the distribution of various particle size ranges below 0.85mm. Generally, we believe the ideal pour-over grind particle size is between 0.6-0.8mm, meaning the higher the percentage of coffee grounds in this range, the better. Therefore, if financial conditions permit, you can purchase several sieves with different mesh sizes.

Particles smaller than 0.3mm are called very fine powder. An appropriate amount of fine powder can enrich coffee flavors, but excessive very fine powder will seriously affect coffee flavor. As for how to define this value, FrontStreet Coffee's standard is 7% as the boundary (though this is not an absolute number).

Perhaps We Can Also Judge by Experience

Of course, in addition to using data to prepare judgments about coffee grind coarseness, we can also determine whether the coffee grind level is appropriate based on the brewing process. First, the brewing time can provide a reference for grind coarseness. According to FrontStreet Coffee's brewing parameter standards, normal extraction time for 1-2 servings of coffee is around 1 minute 50 seconds to 2 minutes 10 seconds. If the grind is too fine, extraction time will be extended; if too coarse, extraction time will be shortened. This can be used to make an initial judgment about whether the coffee grind size is appropriate based on extraction duration.

You can also observe the water flow rate through the coffee grounds during brewing. Under normal circumstances, the coffee bed settles at a uniform, slow speed. If you notice the settlement speed is fast, it might be due to grinding too coarsely. If the settlement speed becomes progressively slower, or even becomes blocked, it might be because the grind is too fine or there's too much fine powder, causing a muddy appearance at the bottom of the coffee bed.

Important Notice :

前街咖啡 FrontStreet Coffee has moved to new addredd:

FrontStreet Coffee Address: 315,Donghua East Road,GuangZhou

Tel:020 38364473