What is coffee extract? How to judge the effect of insufficient extraction and excessive extraction on the flavor of coffee

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Extraction:

It means to squeeze something out or get an extract. In chemistry, extraction refers to the extraction of valuable substances (flavor) from the raw material (coffee beans). In coffee extraction, the most common is to use hot water to extract flavor from coffee powder.

Overextraction:

It means that the contact time between coffee powder and hot water is too long, or the ratio of coffee powder to water is too low. When using drip filter coffee machine and Italian coffee machine, the over-extraction may be that the coffee powder is ground too fine. When cooking by hand, the extraction time may be too long. Excessive water temperature can also lead to over-extraction. Excessive extraction will extract too many unwanted substances, such as caffeine, and make the coffee taste bitter and uneven.

Insufficient extraction:

It means that the contact time between the coffee powder and the hot water is too short to extract all the flavor from the coffee powder, which makes the coffee taste thin, bitter and uneven. Insufficient extraction may be due to the fact that the coffee powder is too coarse or the water temperature is too low. If the ratio of coffee powder to water is too high, you will get underextracted espresso, which not only lacks the characteristics of coffee, but also has a bitter taste.

Refers to the time that coffee powder comes into contact with water, which is a very important factor for good coffee. Other nouns, such as brewing time or soaking time, also refer to extraction time.