How to judge the grindability of hand-brewed coffee? The relationship between grindability and roasting degree of hand-brewed coffee.

The effect of grinding degree on coffee grinding is very important for coffee, good coffee depends on good grinding degree, and the size of coffee particles directly affects the efficiency of hot water for wet extraction of coffee. In theory, the more uniform the coffee particle value is, the more consistent the overall extraction efficiency is, and the better the coffee flavor is. The concentration and extraction rate decrease with the thickening of the grinding degree and increase with the finer the grinding degree. The degree of grinding means not only the size and shape of the coffee after grinding, but also the size of the surface area. The finer the coffee powder is ground, the larger the coffee surface area is, and the more the water touches the coffee, the more substances can be extracted. An increase in the surface area (the thicker the grinding) also allows more carbon dioxide emissions in the coffee beans.

The flavor of coffee is extracted in the order of sour, sweet, bitter and astringent. This means that by controlling the degree of extraction, you can control the amount of each substance being extracted, in other words, you can determine the taste of the coffee. This is the basic goal of creating a brewing formula, whether it's Espresso or brewing coffee. The degree of grinding is one of the keys.

The standard roasting degree of coffee is divided into shallow roasting (light), shallow baking (cinnamon), moderate roasting (medium), medium and deep roasting (high), deep roasting (City), very deep roasting (full City),

The three commonly used baking degrees are shallow baking, moderate baking and deep baking.

With regard to the degree of grinding, the front street is determined by sieving this and the roasting degree of coffee, according to the grinding advice provided by the American boutique coffee association SCA for hand-brewed coffee, and then combined with the actual operation verification.

Shallowness: shallow roasted coffee beans will have a sour taste, while caramel-flavored substances are not easy to extract from the cup. Shallow roasted coffee beans are recommended to use fine grind 0.85mm No. 20 sieve pass rate 80%

Moderate: medium roasted coffee beans in front street are recommended to use fine grind 0.85mm 20 sieve pass rate 75% fine grinding can slow down the time of water passing through the powder layer and better extract sour, sweet, and caramelized substances to balance the coffee flavor.

Ground coffee powder recommended brewing water temperature at 90-91 °C, too high water temperature will be too high to extract caramelized substances, resulting in bitterness, too low water temperature will not extract enough, only some sour substances and sweet substances will be extracted, making the coffee flavor insipid and boring.

Medium-and deep-roasted coffee beans generally have a low sour taste and obvious alcohol thickness, which means that caramel-flavored substances will be more abundant. Qianjie will recommend the use of coarser grinding (70% of 0.85mm 's No. 20 screen pass rate, that is, the size of coarse sugar). Coarser grinding can speed up the time for water to pass through the powder layer, so that caramelized substances will not be over-extracted, and that the flavor and taste of coffee will be sweet and mellow without producing unpleasant bitterness. Medium and coarse ground coffee powder is recommended to brew at 88-89 °C. if the water temperature is too high, the flavor of the coffee will be bitter and difficult to swallow, while the coffee with too low water temperature will be boring and insipid.