Acidity and sweetness from the point of view of Coe cup measurement

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With the continuous development of the coffee market, as consumers, we are not only exposed to more and more producing areas and all kinds of processed coffee. In addition to satisfying the desire for curiosity, the quality identification of a cup of coffee, or even the quality of raw coffee beans, is not only related to the money paid, but also to our health.

The presentation of a cup of coffee goes through planting, processing, roasting and finally extraction. Every step of the process is crucial and will eventually directly affect the sensory presentation of drinking. Today, with the development of boutique coffee, we pursue more and more delicacy and beauty in tasting. Not only pursue the fragrance of birds and flowers, but also hope that the sweet and sour taste is as bright as juice. All this depends not only on superb cooking skills and skillful furnace operation skills, but also on the quality of carefully cultivated raw beans.

The problem is that a good cup of coffee needs to be roasted and extracted. And it all depends on the quality of raw beans. How can we confirm the raw bean quality of this cup of coffee?

From the inspection of raw bean quality, we can see that the COE competition cup testing system of ACE excellent Coffee Alliance and the judgment of raw bean quality of CQI of American Coffee quality Association are the most mainstream criteria at present. Among them, the judgment method of coffee quality learning CQI is a series of processes from the appearance, number of defects, smell and actual cup test of raw coffee beans. The COE system of the Outstanding Coffee Alliance ACE is judged directly by cup test coffee samples.

In addition to judging the appearance and smell of raw beans, we actually analyze the quality of raw beans from the drinking senses. The feeling after the entrance of coffee is nothing more than taste, smell and touch behind the nose. There is a close causal relationship between these sensory presentation and planting and post-processing. From the point of view of COE, the quality is directly reflected in the acidity, sweetness and cleanliness of coffee.

The organic acid in coffee is an important product of plant growth. Empirically, coffee grown at high altitude also means excellent acidity, and we can find that there are rich kinds of organic acids in raw coffee beans. It contains malic acid, citric acid, chlorogenic acid, quinic acid and a small amount of acetic acid, formic acid, succinic acid and so on.

Chlorogenic acid is a good antioxidant, but it has strong bitterness and low acidity in taste. It is also the main source of bitterness and astringency of raw coffee beans. The content of chlorogenic acid happens to be inversely proportional to the altitude of planting (the higher the altitude, the lower the proportion of chlorogenic acid). We can also pay attention to the low acidity and tactile astringency in coffee, which can be used as one of the conditions to judge the quality of coffee. According to the cup test score of COE, the low acidity not only affects the acidity of Acidity, but also affects the cleanliness of coffee Clean Cup.

From the perspective of high altitude planting conditions, sugar plays a very important role in coffee beans, in which sucrose is not only one of the important sources of coffee sweetness, but also an important raw material to create aroma in the roasting process. The content of sucrose is not only related to altitude, according to data, every 300 meters above sea level, the sucrose content increases by 10%. The reason is that the higher the altitude, the lower the temperature of the planting environment, and the greater the temperature difference between day and night, which can slow down the growth rate of coffee and make coffee accumulate more nutrients. And this is why we pay attention to the altitude of coffee cultivation.

From the process of coffee ripening, the content of sucrose increased as the coffee cherry became more and more mature. Unripe fruits still contain a lot of organic acids and have not yet been converted into sugar. The sweetness of coffee increases only when the fruit is ripe and the organic acids in the fruit are converted into rich sugars.

On the contrary, chlorogenic acid and other organic acids have different changes. Firstly, the content of chlorogenic acid decreased gradually before fruit ripening, while malic acid and citric acid increased in varying degrees with the ripening of coffee cherries.

Therefore, in addition to the altitude of coffee planting, the picking of coffee beans is a key factor affecting the quality. The most direct and obvious manifestation of picking immature fruit is acidity and lack of sweetness. Overmature coffee will produce fermented flavor, and even produce defective flavor such as mildew, which will affect the cleanliness of coffee flavor. So pick ripe coffee cherries and avoid mixing with unripe or overripe fruits. In order to ensure that there are bright and sour and lively high-quality raw beans.

The post-treatment process will also have an impact on the acidity and sweetness of the coffee, such as excessive washing and fermentation will make the acid too sharp and increase the content of acetic acid and lactic acid, making the coffee too sour to drink.

When we understand the part of planting and post-processing, we suddenly realize that the bright and lively acidity and delightful sweetness of coffee are not easy to get, not only depending on the planting altitude and microclimate, but also on the rigor and professionalism of the picking and post-processing process. Good acid is as complex and bright as fruit, while bad acid is poor and boring, which is the focus of coffee quality identification. Here we pay more attention to the quality of acid. It's hard to say? The strength of acid is the key point to match with sweetness. from the fruits of our daily life, watermelon is the fruit with high sweetness but low acidity, while pineapple and passion fruit are wonderful fruits with sweetness and acidity. This is what we pay attention to the combination of sweet and sour. Therefore, the combination of sour and sweet is a key point of food cooking.

And the same sour and sweet matching strength, we can find in some preserves, such as sour plum, black plum dried. Wait. When we compare fresh fruit with these sour plums and dried plums mentioned above, we will find that they have similar sweet and sour feelings, but after careful analysis, there is an obvious lack of bright and lively feelings. we might as well do a small experiment after pinching our nose and eating preserves and fresh passion fruits and pineapples. Fresh fruit not only has a sweet and sour sense of jump in the taste, but also has a sense of brightness and complexity. And this complexity is what we call acid Acidity. So in the quality monitoring, we drink not only the degree of acid, but also the quality and complexity of drinking acid.

The complexity of sweetness is easier to understand. If the sweet taste of coffee is not only as sweet as sugar cane, but also as sweet as fruit sugar, the feeling of sweetness will be richer and stronger.

No wonder sweet Sweet and sour Acidity are graded according to quality in the COE score table. Poor quality of sour and sweet not only in their respective projects, but also affect the cleanliness and flavor presentation. And then affect the overall evaluation results of coffee.

The acidity and sweetness of raw beans create the complexity and richness of coffee, while high-quality raw beans are discussed from the point of view of roasting. The sugar content and organic acid content of raw coffee beans directly affect the performance of roasted beans. In the case of sugar, caramelization during baking is a chemical reaction using sugar as a raw material. And can produce a variety of aromatic substances, as well as acid substances with sour taste and caramelized substances with sweet and bitter taste. With the increase of roasting degree, the caramelization of sugar is higher. In terms of taste, the sweetness and bitterness of coffee will increase with the baking degree. On the other hand, sweet aromas such as cream, honey and caramel gradually appear in the aroma, so it seems that high-sweet (sugar) high-quality raw beans can not only give pleasant sweetness in taste, but also give bakers a wide range of room for baking.

The brighter organic acids in coffee, such as citric acid and malic acid, decreased with the deeper the baking degree. The low acidity of chlorogenic acid and quinic acid also decompose and synthesize other complex substances with the deepening of baking degree, which changes the bitterness of coffee.

Combined with the above effects, baking not only directly affects the sense of taste during drinking, but also affects the sense of smell behind the nose after the entrance of coffee. No wonder the baking degree of the COE raw bean competition falls between the shallow density and the end of the explosion, which not only preserves the acidity of the coffee as much as possible, but also minimizes the effect of caramelization on the taste and aroma, so that cup testers can better understand the quality of raw beans. On the other hand, when the coffee is imported, we have a stronger sense of taste and touch in the mouth, so the test of acidity, sweetness and cleanliness is much more important.