Coffee beans need to be roasted.

Coffee beans are the seeds of coffee cherries that grow on coffee trees. Normally, there are two coffee beans in each coffee cherry. When the untreated raw coffee beans are directly soaked in hot water, there is almost no coffee flavor and aroma.

Coffee beans undergo numerous chemical changes in the roasting process and break down thousands of compounds. Coffee roasters hope that when roasted coffee is soaked in hot water, it will have a very good flavor.

Roasting causes coffee beans to change as follows:

● color changes from green to yellow, from yellow to brown, from brown to brown, and from brown to black.

The volume of ● has about tripled.

● density halved

● sweetness will grow out of nothing with the caramelization reaction in the baking process, and then from strong to weak, until it loses its sweetness at last.

Increased acidity of ●

● produces more than 800 aromatic substances.

● coffee beans will burst obviously when they release a large amount of water vapor and high pressure gas.

The purpose of roasting is to optimize the flavor of soluble substances in roasted coffee beans, which will affect the taste of coffee after brewing. Volatile aromas and oils are the main sources of aroma, while oils and ground bean fiber compounds create the Body of coffee. Baking is the beginning of this process. 80% of the taste of coffee is determined by baking. It can be seen that roasting in coffee production is because roasting gives off aroma of coffee and makes different kinds of coffee give out different flavors. Without this process, the unique taste of coffee will be greatly reduced. Roasting causes coffee to produce coffee oil, which gives coffee beans a strong aroma. The most outstanding feature of this fragrance is that it is volatile and soluble in water. Therefore, people can not only ask about the mellow smell of coffee beans, but also pour it into the cup and taste it carefully.

Baking, as the name implies, is to provide heat to coffee beans, causing a series of chemical changes inside. First of all, the starch in raw beans will be converted into sugars and acids because of high temperature, while substances such as cellulose will be carbonized differently. Water and carbon dioxide evaporate, while proteins are converted into enzymes, which combine with the rest of the fat to form an oil film on the surface of coffee beans. Coffee beans swell when roasted, a bit like popcorn, and interestingly, coffee crackles during roasting, just like we use microwave popcorn. But because the skin on the surface of coffee beans is very tough, we usually don't see coffee beans crack like popcorn. Coffee roasting is divided into the following degrees:

1. Very shallow baked Light Roast

In the mildest baking method, the beans are yellowish brown and the aroma and concentration are mild and light, which can be used as a standard for identification in the early stages of baking.

2. Shallow baking / cinnamon baking Cinnamon Roast

As the name suggests, the beans are cinnamon-colored, slightly thicker than very light roasted, and refreshing in taste.

3. Medium baked Medium Roast

The beans are chestnut, sour and bitter have been released, its taste is deeper than light roasting, fresh aroma, mild taste, suitable for brewing American coffee.

4. Medium and deep baked High Roast

The beans are tea-brown and give people a slightly stronger impression than medium-baked beans. The aroma and color are balanced, and the bitter taste is stronger than the sour taste.

5. Deep baking / city baking City Roast

The beans are tea-brown, with a balance between sour and bitter taste, mellow and quite baked.

VI. Very Deep Baking / Deep City Baking Full City Roast

The beans are dark brown, sour and bitter. Because of bitterness, it is suitable for iced coffee.

7. French baking French Roast

Beans are dark brown, because deep roasting, beans contain fat floating to the surface, appears to be bright, bitter, roasted flavor is very strong, suitable for coffee Oulei.

8. Italian baking Italian Roast

The beans are nearly black, bitter and full-bodied, making them suitable for brewing espresso and cappuccinos.