What is caffeine?
Extraction is a critical step in obtaining a cup of coffee. Simply put, it is a part of the soluble substances that water dissolves and brings out when it comes into contact with coffee powder. That is, a cup of coffee is the fusion of water and the substances that are carried out of the coffee grounds by the water.
Extraction directly affects flavor performance
For a cup of coffee, the quality of the coffee beans and roasting factors affect its taste, but the more direct factor is the extraction. The soluble matter in a coffee bean only accounts for 30%, and the rest is wood fiber. The coffee we want is obtained from this 30%, and some of these substances have bad taste. If we do not master it properly during the extraction process, these flavors will enter the coffee and ultimately affect the quality of the coffee.
The essence of caffeine is to restore the taste of coffee itself. To do this, we need to adjust the roast level of the coffee accordingly, because the flavor of the coffee will be transformed into body and bitterness as the roast level increases.
The three stages of caffeine extraction
The first segment is the aroma (flower and fruit) of small molecular polymers and sour substances that are easily dissolved.
The second stage is the aroma of medium molecular weight polymers (nuts, caramel) and easily soluble substances, such as body and sweetness. In comparison, the second stage is the closest to coffee liquid, but has a little less aroma.
The third section is macromolecular polymer aroma (spice, resin) and insoluble substances.
Among them, the small-molecule polymers in the first stage are the most abundant during medium-light baking, while the medium-molecule polymers are the most abundant during medium-dark baking, and the macromolecular polymers are most abundant during deep-baking.
Create a brewing plan based on the degree of roasting of the beans
When we get the roasted coffee beans, we can judge the roasting degree of the coffee according to the appearance, color and smell. Correspondingly, we will know what kind of water temperature and water flow are needed for extraction, and the degree of grinding thickness can also be specified.
① When the coffee is roasted at medium and light levels, we need to retain its flavor and aroma, so fine grinding, high water temperature, and thin water flow are required;
②When the coffee is roasted at medium and deep level, the taste is comprehensive and needs to be better controlled to avoid extreme conditions and sharp sourness;
③ When the coffee is deeply roasted, the fruit acid is reduced, but the mellowness and bitterness are obvious. It should be brewed with coarse grinding, low water temperature and high water flow to avoid bitterness.