Before going into detail about brewing, we’d like to cover the core principles of coffee extraction. Brewing coffee is always a delicate game — balancing the quantity of coffee, the quantity of water, the type of grind, and the extraction time. Depending on the method, these factors can be varied in order to highlight specific attributes of a coffee.
Remember that a coffee drink is typically around 1.5% coffee and 98.5% water — any minor change can radically alter the end result.
If you increase one end of the equation, you must lower the other, and vice versa. For example, if you are working with a fine grind, and the coffee is getting over-extracted, you can reduce the amount of coffee you are using, holding constant the water temperature and the extraction time. Another example: if you are working with a lower water temperature, you should increase the extraction time and keep the other variables constant. And so on.