The color and smell of coffee represent the quality of coffee.

The color, aroma and taste of coffee are caused by some complex chemical changes that take place during the baking process. Therefore, raw beans must go through appropriate chemical procedures to achieve the most balanced state of its essential ingredients in order to be regarded as the best baked beans. The aroma of coffee changes with the heat, so the baking time should be shortened as much as possible, and the heat should be controlled at the lowest temperature that can produce effective chemical composition of coffee beans, that is, the time and heat of the shortest process, so that coffee beans can produce the most suitable composition ratio.

Fragrance

Aroma is the life of coffee quality, and it can best represent the coffee production process and baking technology, as well as the climate, elevation, variety, refined treatment, harvest, storage, and the appropriateness of baking technology in the consuming country. The results of gas chromatographic analysis showed that the aroma of coffee was composed of acid, alcohol, acetaldehyde, ketone, ester, sulfur compound, phenol, nitrogen compound and nearly hundreds of volatile components. Generally speaking, fat, albumen and sugars are important sources of aroma, while lipids blend with the sour and bitter of coffee to form a smooth flavor. Therefore, the disappearance of fragrance means that the quality is getting worse, and the relationship between aroma and quality is very close.

The basic taste of coffee is the intensity of bitterness and the texture of bitterness. Raw beans contain only a very small amount of bitterness, followed by sugar, partial, fibrous caramelization and carbonization caused by baking to produce the most symbolic bitterness of coffee. Caffeine, one of the bitter ingredients, is also an important substance showing the pharmacological characteristics of coffee, and its content varies according to its type, purification and baking degree. if the baking temperature is high, its content will be reduced, so the shallower the roasting is, the stronger the pharmacological effect of caffeine is, and the deeper the roasting is, the weaker it is. Generally speaking, the bitter taste of strong coffee will be weak, while the bitter taste of coffee is easy to be insufficient, so the proportion of sour taste and bitter taste gives the development space of coffee taste. The bitter taste mainly depends on the baking time, firepower and firepower, but it will also be affected by the soaking temperature and soaking time, so the bitter taste of the coffee that you want to brew is high and refreshing, in addition to the good quality of raw beans, but also need to have a wealth of knowledge and technology of baking to soak.

Sour taste

The sour taste must be affected by the quality and variety of raw beans. As far as the elevation of the variety is concerned, coffee grown in highlands is sour than that in lowlands, and beans just harvested are sour than beans that have been harvested for a while. The increase and decrease of acid varies with different kinds of acid. generally, the beans with shallow baking are rich in sour taste, and those with deeper baking degree are lack of sour taste. Just harvested beans, good quality, high moisture content, if the appropriate heat to produce a moderate sour taste, will make the coffee taste better, make people feel more deep.

Concentrated alcohol

Generally speaking, we use strong alcohol to show the round, mellow and strong taste of coffee. The unique sweetness of high-end coffee is related to the bitter taste, so the refreshing taste must have a sweet taste. In the baking process, part of carbohydrates such as sugar will be caramelized, and the rest will form sweetness. the product of moderate sweetness will be easily lost if it is overheated in the process of baking and baking.