Extracting coffee is the most important and least understood aspect of coffee brewing.
Because it decides everything - flavor, state, acidity and aroma. However, most coffee lovers really have no idea what coffee extraction means, sacrificing the quality of the coffee.
We must first understand the principle of coffee extraction:
Coffee brewing is the process of mixing ground coffee and water, and the water pushes out the moisture from the acids, oils, and other items in the ground coffee.
It sounds like magic, but it's not, it's not magic, it's not incomprehensible science, it's just sucking water out of the coffee beans, it dissolves and disperses something, and turns the water into liquid coffee.
Some substances, like acids and sugars, are quickly extracted and dissolved, but others, such as oils and solid particles, take longer, and bitter substances take longer to come out.
A well-balanced extract with rich flavors, wonderful aromas, a rounded flavor profile with balanced acidity, crispness, and even bitterness.
Let's check the 3 signs of coffee overextraction:
1. Overcome Bitterness
In fact, bitterness is a misunderstanding of taste.
The best coffees in the world can still have a bit of bitterness, usually in the form of dark chocolate, spice or wood. These understated flavors round out the coffee flavor, balance out the more prominent acids, and are generally welcome in a full cup.
However, some coffees have some incomprehensible bitterness that doesn't add depth or complexity to other flavors, but rather dulls the coffee. In fact, this bitterness is caused by the over-extraction of some bitter chemicals from the coffee grounds.
2. Tasteless and emptiness
Sometimes, over-extracting bitterness doesn't just overshadow other flavors a little, but it can kill other flavors completely, leaving your coffee lifeless, dull, and boring.
Think back if you've ever had your imaginary gourmet coffee, only to find it was particularly dull and tasteless, when in fact, as long as it wasn't an old bean, it was over-extracted.
Under-extracted coffee can also have a thin, dull taste, but that's another story. In this case, there is a strong sour taste because other balanced flavors have not yet been pulled from the coffee grounds.
3. Dry sandpaper taste
Have you ever tasted coffee that makes your tongue feel dry and itchy? Have you ever thought that coffee can completely absorb the moisture in your mouth? In fact, this is the so-called astringency.
The same thing happens when drinking black tea or dry wine, but in coffee it's a classic sign of overextraction. This feeling is usually caused by the traces of polyphenols commonly found in a variety of plants.
These chemicals create a bitter taste and bind to your salivary proteins, absorbing your tongue's natural lubricants and giving it a dry feel.