What is the relationship between the concentration of hand-brewed coffee and the extraction rate? The solution to the problem that hand-brewed coffee is too strong to drink.

Guide reading

Nowadays, most of the hand-brewed coffee is floral and fruity-flavored coffee beans. Sometimes make a cup of fragrant coffee, smell to the nostrils, but taste but the flavor is vague, difficult to identify, sensory experience uncomfortable. However, when 10-20ml water was added to the coffee solution, the flavor became clear.

Bitterness caused by excessive concentration is not necessarily over-extraction.

Beginners often drink coffee with uncomfortable bitterness, which is directly linked to the extract. In fact, this is not accurate. First of all, let's understand what the extraction rate and concentration represent.

The extraction rate refers to the proportion of substances extracted from coffee beans. 30% of the substances in coffee beans can be dissolved in water, and an extraction rate of 18-22% is considered reasonable. If the extraction rate is higher than 22%, there is a risk of over-extraction.

The concentration generally refers to the content of the substance in the coffee liquid, and the concentration of hand-brewed coffee is not too high, usually less than 2%.

The relationship between the two is linked by "water", that is, we use "how much water" to take away "how many substances of coffee powder" in the process of making coffee. "how much water" is what we often call the ratio of powder to water, and the proportion of water "how much coffee takes away" to the total liquid is the coffee concentration.

For example, in a coffee brewing experiment in Qianjie, Ethiopia's Huakui coffee was brewed, using a powder-to-water ratio of 1:15, passed a concentration test of 1.49%, and calculated an extraction rate of 19.66% (between 18 and 22%). And in the range of low), completely in the reasonable range of extraction rate. Can be tasted but the flavor is vague, and has a slight sense of bitterness. Then add 20ml water to the coffee, and shake it evenly, pass the concentration test to 1.22%, taste again, the bitterness is obviously relieved, the acidity of berries, honey rhyme and fermentation flavor can also be clearly distinguished, and the whole taste bud experience has been improved.

What causes it? First of all, the senses of the human body are complex and fastidious about flavor, just as we can't resist sugar, but we reject eating white granulated sugar directly, because the purity of sugar is too high, resulting in sweetness. The same is true of fruit juice concentrate, it will feel uncomfortable to drink it directly, but when diluted with water, it will become comfortable and delicious.

The taste of coffee is complex, the combination of sweet, sour and bitter, if the concentration is too high, it will lead to excessive concentration of flavor substances, taste buds can not clearly identify the flavor, and will bring a sense of astringency and excessive bitterness. With the addition of clear water, the overall substance in the coffee liquid did not change, but the space of each molecule became larger, so that the taste buds could more easily identify other flavors.

Coffee with a lower concentration is popular.

For the deep-roasted hand-brewed coffee in the past, people prefer a high concentration of thick taste (although the taste is not directly related to the concentration, but the mellow coffee concentration is actually very high). But now the light-roasted hand-brewed coffee will use more powder than to show the coffee flavor, more and more people tend to 1:16 or even higher powder-water ratio, showing a cup of light, rich coffee.