What is the Ideal Grind Size for Pour-Over Coffee? How to Adjust Coffee Bean Grind for Pour-Over Brewing

Coffee Grind Size: An Obstacle You Cannot Avoid

According to FrontStreet Coffee's experience answering questions for many friends, over half of poorly brewed coffee is 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 cafés nowadays is basically freshly roasted coffee beans ground and then brewed, which leaves grounds. Coffee needs to be ground into powder before brewing because this releases coffee substances much faster than brewing whole beans.

The finer the grind, the larger the surface area of the coffee particles, and the faster the coffee substances are released.

How Coarse? How Fine?

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

When ground too coarse, the gaps between coffee particles become larger. On one hand, coarser grinding releases substances more slowly, and on the other hand, water flows down more quickly. This can easily lead to lighter taste, weaker bitterness, reduced acidity, fewer off-flavors, and a cleaner cup.

Therefore, a suitable grind size for pour-over needs to balance both particle size and water flow rate. Generally, the extraction time for 1-2 servings of pour-over coffee is controlled around 2 minutes. According to the SCA cupping grind size calibration standard (which requires a 70-75% pass-through rate for a #20 sieve), the grind requirement for pour-over is finer than cupping, so the pour-over grind size should have a 75-80% pass-through rate for a #20 sieve. This grind setting can be roughly understood as what many coffee shops call "fine grind for pour-over."

The calibration of a #20 sieve has a drawback: it can only separate coffee particles larger than 0.85mm from those smaller than 0.85mm. It cannot distinguish the distribution of various particle size ranges below 0.85mm. We generally believe that 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 economic conditions permit, you can purchase several sieves with different mesh sizes.

Particles smaller than 0.3mm are called very fine particles. An appropriate amount of fine particles can enrich the coffee's flavor, but excessive very fine particles will seriously affect the coffee's flavor. As for how to define this value, FrontStreet Coffee's standard is 7% as the boundary (there's no absolute number).

We Can Also Judge by Experience

Of course, besides using data to determine coffee grind fineness, we can also judge whether the coffee grind level is appropriate based on the coffee brewing process.

First, brewing time can provide a reference for grind coarseness. According to FrontStreet Coffee's brewing parameter standards, the 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, the extraction time will be extended; if the grind is too coarse, the extraction time will be shortened. This can be used as an initial judgment of whether the coffee grind size is appropriate based on extraction duration.

You can also observe the settling speed of the coffee ground layer during brewing. Under normal circumstances, the ground layer settles at a uniform slow speed. If you notice the settling speed is fast, it might be due to too coarse grinding. If the settling speed becomes slower and slower, or even gets blocked, then it might be due to too fine grinding or excessive fine particles, with the bottom of the ground layer appearing muddy.

Important Notice :

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FrontStreet Coffee Address: 315,Donghua East Road,GuangZhou

Tel:020 38364473