Why coffee is bitter in taste

I'm not particularly enthusiastic about bitter tastes in general, much less when it comes to coffee. And believe me when I tell you that I am a coffee addict!

I know that experts in the field will find this contradictory and strange, but as a famous saying goes: "Between tastes and colors, the authors have not written."

I will never forget when a friend of Arab descent invited me to his house for coffee. I had high expectations of trying this coffee. When the time came, sitting comfortably at a table in the garden, he kindly offered me a tiny cup of coffee, I relaxedly took my sip, but it was so bitter that I could not hide it in my face. My friend just then laughed out loud and proceeded to feast on his delicious bitter coffee.

I love that the coffee I wake up within the morning is full of flavor, but not bitter. Many believe that the darker and more bitter the coffee is, the better because you will get a more robust and more caffeinated cup of coffee to vitalize the day, but let me tell you something: this is a mistake.

The coffee must have good taste, and we should not disguise its flavor with sugar or cream, something that I did when the coffee was too bitter for me. In the world of coffee, acidity is many times more appreciated than bitterness, and the latter can even be considered a defect. It is not easy to distinguish between bitterness and acidity.

What is bitterness?

young lady taste bitter on her coffee

Bitterness is simply a lack of sweetness. Acidity depends on the presence of an acid, bitterness, and sweetness rely on the interaction of specific molecules with the taste buds.

There are many theories and studies carried out to try to clarify this mystery. There is a study by Dr. Marilyn Cornelis and her team of Preventive Medicine at Northwestern University in the United States.

With a group of more than 400,000 Britains, they analyzed the relationship between the sense of taste and their love of coffee. The results showed that the people most sensitive to the bitter taste of caffeine are also the ones who consume the most cups of this black concoction. This contradicts common sense or logic.

Dr. Cornelis explains that this is possible due to a 'positive reinforcement' that makes individuals who best distinguish the bitter taste of caffeine learn to associate that bitterness with its positive effects.

That association, assures the American researcher, would counteract the natural aversion that, in theory, should cause us to consume a drink as bitter as coffee.

So, those who are more sensitive to bitterness tend to savor the bitterness of coffee more and associate it with something good. It does not only happen with coffee, but with bitter drinks. Yet some experts say that the reason is much simpler; that we don’t know how to prepare our coffee.

What things make coffee too bitter?

black coffee with sack of beans

I dedicated myself to investigate on the subject to prepare the coffee to my liking, and I realized that there are significant factors that influence the taste to be more or less bitter and they are the following:

Roasting is too dark

Roasting too dark can burn the coffee, and that bitter taste can be the result of a breakdown in the molecules due to this. In my case, I leaned for medium roast coffee. This type of coffee tends to taste less bitter than dark roasted coffees.

That's because medium roast coffee is generally roasted for a shorter time and at a lower temperature than dark roasted coffees.

The equipment is dirty

The sediments in the frets and espresso machines can make the coffee taste bitter since these are burned more and more with each extraction.

Every time we prepare the coffee, we must make sure to rinse all the equipment after using it.

The grinding is too fine for the extraction method

A too fine grinding does not allow the water to pass at the necessary speed so that the contact with the hot water does not burn the coffee.

The grinding must correspond to the pressure that will be produced in the extraction, hence for extraction of espresso, a finer grinding is used (very high pressure), and for a filter extraction, a thicker grinding is used (very little pressure).

The extraction process

When I speak of extraction, I am referring to the process by which water soaks the ground coffee particles, dissolving all their components to a greater or lesser extent.

This process must be done correctly to keep all the flavor notes of the coffee beans and avoid the bitter ones. Mixing the water with the coffee beans produces a chemical reaction that extracts a great wealth of flavors and nuances.

The coffee can be bitter if the total extraction time is longer than it should, something that usually happens if you use the French press since people tend to wait and let the coffee rest once the plunger has gone down.

If you leave the water submerged too long with the beans, it continues to transfer flavor, but the best notes have already been extracted.

On the other hand, the extraction time has been short, the water has not been able to extract enough flavor from our coffee. When this happens, the coffee leaves an unpleasant acid aftertaste with salty notes in our mouths.

Verify that the water you use is not too hot

Another reason why coffee prepared at home could have a bitter taste is that we have used too hot water to make it.

Preparing it with too hot water can cause it to taste more bitter. The water temperature should be between 90c (195f) and 96c (205f).