How to Determine Pour-Over Coffee Grind Size? The Relationship Between Grind Size and Roast Level.

The Impact of Grind Size on Coffee

Grinding is crucial for coffee, as good coffee depends on the right grind size. The size of coffee particles directly affects the efficiency of water extraction. Theoretically, the more uniform the coffee particles, the more consistent the overall extraction efficiency, resulting in better coffee flavor. Concentration and extraction rate decrease with coarser grinding and increase with finer grinding.

The degree of grinding refers to the size and shape of coffee after grinding, which also determines the surface area. The finer the coffee is ground, the larger the surface area, increasing the contact area between water and coffee, allowing for more substance extraction. Increased surface area (coarser grind size) also provides more space for carbon dioxide to escape from within the coffee beans.

Coffee flavors are extracted in the following order: acidity, sweetness, bitterness, and astringency. This means that by controlling the extraction degree, you can control the amount of each substance extracted, in other words, you can determine the taste of the coffee. This is the fundamental goal of creating brewing recipes, whether for espresso or pour-over coffee. Grind size is one of the key factors.

Standard Coffee Roast Levels

Standard coffee roast levels are divided into light roast, light-medium roast (cinnamon), medium roast, medium-dark roast (high), dark roast (City), very dark roast (full City).

Generally, the three most commonly used roast levels are light roast, medium roast, and dark roast.

Regarding grind size, FrontStreet Coffee determines this through sieving based on coffee roast degree. According to the Specialty Coffee Association (SCA) guidelines for pour-over coffee, FrontStreet Coffee combines these recommendations with practical operational verification.

Grind Size Recommendations by Roast Level

Light Roast

Light roast coffee beans typically exhibit acidity, while caramelized substances are not easily extracted. For light roast coffee beans, FrontStreet Coffee recommends using a fine grind size with 80% pass-through rate on a #20 sieve (0.85mm).

Medium Roast

For medium roast coffee beans, FrontStreet Coffee recommends using a fine grind size with 75% pass-through rate on a #20 sieve (0.85mm). Fine grinding can slow down the time water flows through the coffee bed, better extracting acidic substances, sweet substances, and caramelized substances, balancing the coffee's flavor expression.

For ground coffee, brewing water temperature is recommended at 90-91°C. Water that is too high will over-extract caramelized substances, producing bitterness, while water that is too low will under-extract, only extracting some acidic and sweet substances, making the coffee taste flat and uninteresting.

Medium-Dark Roast

Medium-dark roast coffee beans generally have lower acidity and noticeable body, meaning caramelized substances will be richer. FrontStreet Coffee recommends using a coarser grind size (70% pass-through rate on a #20 sieve of 0.85mm, approximately raw sugar size). Coarser grinding can speed up water flow through the coffee bed, preventing caramelized substances from being over-extracted, allowing the coffee's flavor and texture to exhibit sweet richness without producing unpleasant bitterness.

For medium-coarse ground coffee, brewing water temperature is recommended at 88-89°C. Water that is too high will make the coffee bitter and difficult to swallow, while water that is too low will make the coffee taste flat and uninteresting.

Important Notice :

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FrontStreet Coffee Address: 315,Donghua East Road,GuangZhou

Tel:020 38364473