Why does coffee taste sour? How to reduce the acidity of coffee? Why is coffee sour?

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Acidity is the key to determine the quality of coffee, acidity and acidity may be the performance of taste defects; fresh and bright are the necessary characteristics of high-quality coffee.

"I would like to stress here that acidity is not good. What we want is a fresh, bright and complex sour taste, similar to sweet oranges or oranges. This is the taste characteristic valued by coffee experts and boutique coffee lovers."

So, how can we avoid extracting negative sour taste while ensuring that the sour taste of coffee is soft and juicy?

What kind of sour taste you can extract depends first of all on the taste characteristics of the coffee itself, so be sure to know your coffee beans in advance.

Is coffee high-density or low-density? High-density coffee grows at high altitudes and lower temperatures, and its fruity and acidity are usually stronger.

How do you deal with raw beans? Is it washed, insolated or honey treated? Raw bean treatment refers to the process of peeling off coffee beans from coffee fruit, which will have a profound impact on the taste of coffee. Sun-and honey-treated coffee usually tastes sweet and mellow, while washed coffee tastes pure and sour.

How is coffee roasted? Is it deep, moderate or mild? The deeper the roasting, the more bitter the roasted coffee will be, while the lightly roasted coffee will reflect the natural sour taste of coffee.

Water: the most important ingredient of coffee

Do you know? 94-98% of coffee is water, so the quality of water will have a great impact on the quality of coffee.

Let's start with the softness and hardness of water. Hard water has high mineral content, especially magnesium and calcium, while soft water has even lower mineral content.

Steve Cuevas, winner of the 2017 US Coffee Cup Test Competition, said: "the higher the mineral content of the water, some minerals will neutralize the acid in the coffee, resulting in a lower sour taste." At the same time, higher mineral content will also accelerate the extraction of coffee, resulting in a more bitter taste. "

Thomas Chandler, a molecular scientist and coffee roaster, said that carbonate is the main ingredient that affects the sour taste of coffee. The higher the content of carbonate, the lower the sour taste of coffee. Of course, whether the effect of carbonate is obvious or not, it is necessary to comprehensively consider the content of other minerals.

In contrast, soft water has a higher content of sodium ions, which makes the sour taste of coffee more prominent.

But this does not mean that the softer the water quality, the better. The water with higher calcium and magnesium content can extract more flavor from the coffee. On the contrary, it will improve the quality of the coffee.

So, what's the solution?

Change the brewing formula

The combination of water and coffee powder creates a fascinating taste of coffee, and adjusting the ratio of water to coffee powder can greatly change the taste of coffee.

In addition, the brewing time, grinding parameters, water temperature and other factors will affect the extraction degree of coffee.

This not only refers to the intensity of the coffee, but also refers to what substances and how many substances will be extracted from the coffee.

At the beginning of the extraction, fruit acid is extracted first, followed by sweetness, which makes the coffee taste more balanced, and finally bitter. Therefore, coffee that is not fully extracted is usually sour, while coffee that is overextracted is usually bitter. The ideal extraction state is that the coffee has the best sweetness, taste balance, taste and acidity.

1. Grinding parameters and extraction

Each kind of coffee and each brewing equipment corresponds to different grinding parameters, but in general, we can control the sour taste of coffee by adjusting the grinding parameters.

The extraction rate of coarse ground coffee powder is slower because the contact area between coffee powder and water is smaller, which means that rough ground coffee can reflect the fresh sour taste. So my advice is: if you want coffee to be sour, grind it thicker; if you want coffee to be less acidic, grind it finer.

Of course, the grinding parameters are only one of the many factors in the brewing formula. The ideal grinding parameters should depend on the characteristics of coffee, for example, the solubility of deep-roasted coffee is higher and the extraction rate is faster, so the grinding degree should be thicker.

two。 Brewing time, extraction and acidity

Brewing time is another major factor affecting the degree of coffee extraction. The longer the brewing time, the higher the degree of extraction of the coffee.

No matter how good the coffee beans are, no matter how high the water quality is, and no matter how accurate the grinding parameters are, if the brewing time is wrong, your coffee will become tart or insipid.

The Barista Hustle team stressed that grinding parameters can only change when substances are extracted, not what substances are extracted. No matter how rough the grinding is, if you brew for too long, your coffee will lose its sour taste; similarly, no matter how fine the grinding is, if the brewing time is too short, your coffee will also taste sharp.

3. Control the water temperature and highlight the sour taste

Another major factor affecting coffee extraction is the water temperature. Even a temperature difference of 1 ℃ can make a big difference in the sour, sweet and other flavors of coffee, said Joe Behm, founder of Behmor and designer of SCA-certified intelligent coffee brewing and baking equipment.

The higher the water temperature, the faster the coffee extraction rate; the lower the water temperature, the slower the coffee extraction rate. At the same time, some substances cannot be extracted if they do not reach a certain temperature (which explains why cold-extracted coffee has low acidity).

All in all, in order to adjust the sour taste of coffee, please try to change your brewing formula, try to use different quality of water, with different water temperature, grinding parameters and brewing time, to extract the most elegant sour taste of coffee!