Is the acidity in coffee an advantage or a disadvantage? Why is some acidity pleasant while some makes people frown? Starting from the sources and perception of acidity, this article analyzes one by one the meanings of tasting terms such as clean, balanced, body, and complexity, and introduces the four major appreciation principles of acidity, body, aroma, and flavor. At the same time, drawing on Front Street Coffee's brewing experience, it helps enthusiasts clarify the difference between good acidity and bad acidity, grasp the effects of adding sugar and extraction temperature on flavor, and thereby truly understand how to describe and appreciate the layers and personality of a cup of specialty coffee.

We usually come into contact with many different types of acidity—lemon, apple, wine, balsamic vinegar, and so on. The reason these foods are so appealing is that acidity plays an indispensable role. Similarly, if a cup of coffee has beautiful acidity, it is often precisely the key to its high praise.

In fact, all coffee has acidity, because green beans themselves contain a large amount of organic acids, and during roasting these acids transform into various aromatic acids or pungent acids. However, once the temperature is high they are burned off again, so the darker the roast, the weaker the acidity usually is. Judging whether acidity is good or bad is not difficult, just as you can easily distinguish the acidity of fruit from the stinging sensation of hydrochloric acid. If the brewing water temperature is too low, or the extraction is excessive, substances such as tannic acid and nicotinic acid in the coffee will enter the mouth, stimulate the lower sides of the tongue, and come with a pungent odor, causing discomfort.

This kind of acidity is completely different from delicious acidity. Strong acidity stimulates the edges on both sides of the tongue, bringing sensations such as "thin" and "sharp"; while soft acidity, in addition to the sides of the tongue, can also be evenly experienced in the area near the middle of the back of the tongue, and some soft acidity even approaches saltiness (such as the acidity of tomatoes and plums) or a soda-like sensation. Because prominent acidity often overwhelms body and becomes the protagonist of taste, some people use "clean" and "bell-like clarity" to describe coffee with vivid acidity. The aroma of acidity gives the acidity itself more layers. Certain slightly pungent aromas can refresh the mind and make people notice instantly, producing a feeling of "brightness"; conversely, some aromas give a gloomy feeling. For example, soda, lemon, apple, tomato, and ripe banana decrease in brightness in that order. Most people dislike coffee acidity, probably because they are not used to the coexistence of acidity and bitterness. Fortunately, acidity can be suppressed by sweetness, just as everyone can accept lemon juice with sugar added. If you find the coffee too acidic, you might as well add some sugar—unlike milk, sugar not only does not interfere with other rich and mellow flavors, but also enhances the coffee's sweetness.

Clean: The coffee has no earthy taste, is not wild, and has no defects or dazzling distinctive features.

Balance: It has sufficiently complex and striking characteristics, but no single characteristic stands out especially.

Body, Mouthfeel: Body refers to the thick, viscous, slippery tactile sensation of coffee in the mouth, roughly proportional to the amount of colloidal suspension in the coffee. The entire oral cavity feels body, so we use "full" to describe thick coffee and "thin" to describe the opposite situation. Coffee with thin body drinks like wine or lemonade, while full-bodied coffee drinks like whole milk or syrup.

Complexity: Refers to the coexistence of different layers of characteristics in the same cup of coffee. High complexity means that more types of sensory stimulation can be felt; note that these sensations include the aftertaste and are not necessarily limited to the moment of drinking.

Depth: This is a relatively subjective descriptive term, referring to resonance and appeal beyond sensory stimulation, which may come from some delicate sensations or from complex interactions among different sensations.

Bitter: This is a characteristic of dark-roasted beans, and like acidity, it is not necessarily unpleasant; it is a sensation of the entire oral cavity and throat, not just the tongue. Friends who often drink Americano or siphon coffee may use "intense" to describe this characteristic.

Sweet: It has two layers of meaning. The first layer is the stimulation of sugar on the tip of the tongue, namely what is generally called sweetness; the second layer refers to the mellow sweetness formed from Full City roast to Espresso roast by some astringent substances together with rich body, reminiscent of syrup; this kind of sweetness does not require an obvious reaction on the tip of the tongue.

Smooth: Refers to a sweet Espresso with weak acidity and bitterness that can be comfortably drunk with a little sugar and without milk.

Tasting coffee is not only about drinking, but also about smelling. Although there is no absolute formula for judging coffee as good or bad, mastering the following four appreciation principles commonly used by connoisseurs will still help you understand coffee and thereby know how to taste it:

Acidity

The taste that lingers lightly on the tip of the tongue after coffee enters the mouth. The word "acid" may look harsh, but in fact the original fruit flavor and fresh vitality of coffee beans, like wine, are contained in their acidity. The acidity released by fresh coffee carries the fragrance of fruit, like the natural fruit acids contained in fruits such as lemon, grape, and apple, pleasant and fresh in taste, and it must be distinguished from another word used to describe expired, spoiled coffee—sour. In coffee, Yemen "Mocha" coffee is famous for its strong acidity. Front Street Coffee's roasters also often remind us that whether a bean's acidity is clean often determines its overall performance in the cup.

Body

The taste sensation that lingers on the back of the tongue and in the oral cavity after sipping coffee—is it intense or light? Coffee with a mellow body, even if the coffee powder concentration is not high, can still bring a strong taste vibration. Generally speaking, Mexican coffee has the lightest taste, while Sumatra (Mandheling) coffee has the strongest body. Full-flavored coffee is best when blended with milk, highlighting its authentic rich and mellow taste that cannot be masked. When recommending Mandheling, Front Street Coffee also often suggests using this method to experience its fullness.

Aroma

The mellow fragrance of coffee drifting through the air. From roasting, grinding, to brewing, coffee beans exert themselves to the utmost to release fragrance at every stop of their long journey. Therefore, you might as well make good use of your sense of smell and, along with the coffee, experience this aromatic journey together.

Flavor

The coffee impression pieced together by connecting the above three. Some coffees have diverse flavors, with acidity, sweetness, and bitterness all present; others have acidity that is extremely overflowing, completely occupying your sense of smell and taste. Some people are also used to letting "feeling" dominate their judgment—does the coffee have its own style? Does it have a distinctive forest or fruit aroma? Is its temperament gentle or masculine? This is the most private and emotional stop in the entire tasting process. Front Street Coffee believes that there is no standard answer for flavor, but every serious cupping is a deep conversation with coffee.

The above content is compiled by CoffeeHunters, a coffee news website.