The characteristics and advantages of Coffee pre-soaking affect the factors of pre-soaking

Professional coffee knowledge exchange more coffee bean information please follow the coffee workshop (Wechat official account cafe_style)

The pre-soaking stage (or steaming stage) is the first stage of hand flushing or dripping. Pour a small amount of water first, just enough to soak all the coffee powder, and then the pre-soaking period is about 20-30 seconds. This step has a simple purpose: to release carbon dioxide.

During the roasting process, the organic matter inside the coffee beans changes, producing carbon dioxide. (roughly speaking, slightly roasted coffee beans have higher internal water content, so there is not as much gas inside the beans as deep-roasted coffee beans, especially those that enter the second explosion will release more carbon dioxide. )

Coffee beans continue to exhaust after roasting, so in the process of brewing, when the coffee powder comes into contact with hot water, the coffee powder begins to release the gas inside the coffee. This is the reason for the expansion of coffee powder. As you might expect, the more gas spills out of the coffee powder, the bigger the drum will be.

The importance of steaming is twofold: first, carbon dioxide itself has a sour taste that you don't want to taste when drinking it. There is a difference between this sour taste and the bright sour smell in coffee. ) so letting these gases out during steaming can avoid bringing this sour taste into the coffee liquid and better ensure the taste when you drink it.

Second, when the coffee powder removes the gas, the gas forms a force that pushes your injected hot water toward the edge of the coffee powder, which affects the extraction of the coffee. As a result, the coffee powder on the top and edge may be over-extracted, but not enough on the inside. However, after the gas is discharged, many small pores will be formed between the coffee powder, so that the coffee powder can be in better contact with water and can fully and evenly extract the ingredients in the coffee. So this is also the necessity of steaming.