Common sense of extraction principle of hand-brewed coffee

Before extraction, let's popularize a little common sense:

First, coffee beans have both high-quality flavor and defective flavor.

Second, the aromatic substances of coffee will be dissolved first, and the bad substances will be dissolved later. So we are very lucky, if the aromatic substances and bad substances are dissolved at the same time, then the taste of coffee.

According to the above two points, what we need to do is to extract as many high-quality parts as possible, that is, aromatic substances, or essence, and extract as few defective substances as possible, which can also be called dregs. This process is extraction, which literally means extraction.