Coffee roasting is an important factor in determining the quality of fine coffee

Whether at home or abroad, coffee experts or coffee predecessors all call the flavor of coffee "aroma and flavor" or "aroma and taste". Aroma is an important factor in the flavor of coffee. The aroma that attracts coffee lovers is produced by roasting. The so-called roasting is: fried raw coffee beans, raw beans through baking will produce aroma components.

Does roasting coffee beans sound tempting? Long after the discovery of coffee, the soup was boiled to drink, and then it was found that the natural delicacy of coffee would be perfectly reflected only when it met with fire. it can be said that without baking technology, there would be no such worldwide drink as coffee now.

Coffee roasting and color

Raw coffee beans are light turquoise and gradually turn brown and dark brown as the drying process deepens. In the past, this brown pigment has been thought of as a carbonized product of sucrose and amino acids, which we often call burnt. In addition to those things mentioned above, it is also related to chloroquinic acid, which is unique to raw beans.

Coffee roasting and grading

Roasting must be based on the type, characteristics and usage of coffee beans, whether it is used for individual coffee or for blending coffee to determine the degree of roasting. It can be roughly divided into three categories: shallow baking, moderate baking and deep baking. There are also levels that are subdivided, so there will be as many as 8 levels.

Roasting and taste of coffee

The indispensable sour and bitter taste of coffee is caused by sucrose and fructose in the process of coffee roasting, and it is also formed by roasting. Although these coffee beans vary from bean to bean, but the degree of roasting also varies a lot. Among them, the biggest change is the aroma, there are only a few kinds of aroma before baking, and it will increase to hundreds after baking, of course, these aromas will not be shown all at once, and the aroma will be different with different degrees of baking.

The shelf life of fresh coffee is very limited, no matter how much effort you put into the packaging of the coffee, its shelf life is still limited.

A coffee bean contains 12% moisture, 49% carbohydrates, 11% protein, 14% fat and wax, 7.6% chlorogenic acid, a small amount of alkaloids, caffeine, alkaloids, and trace elements (calcium, copper, potassium, iron). In the process of roasting, coffee beans undergo physical and chemical changes, which determines the quality of their taste.

Modern baking hot air method

When the coffee is roasted in a fluid bed, the coffee beans will be blown in a conical container up to 600 degrees for 4-10 minutes, which is enough to change the color of the coffee beans, but the taste of the coffee can not be completely released and the taste can not be generated properly. this method is usually used by some large roasters, and it is sufficient for coffee that is generally produced and baked for less than 8 minutes. Another method, often referred to as high-yield or lightning baking, can be baked for 90 seconds at a temperature of 800 degrees Celsius.

Traditional baking direct fire method

This method ensures the quality of the coffee, and it takes 15-25 minutes, and in the first 12 minutes, the coffee beans are heated to about 160 degrees Celsius, and through a series of reactions, the sugar and protein in the coffee react and form substances with aroma and color, which decompose and fission in the following reaction, thus forming a unique fragrance, and the color of the coffee beans is deepening.

The four main aromas of coffee are formed below 200 degrees, which is reached within 18 minutes. The color of coffee beans is light gold at 130 degrees, light brown at 170 degrees, brown at 200 degrees and black-brown at 230 degrees.

After about 5-10 minutes, the water in the coffee bean evaporates completely, and the content of sugar and caffeine will be greatly reduced, and the weight of the coffee bean will disappear by 20%, but its volume will increase by about 50%. Under the action of heat, the coffee bean will produce a lot of carbon dioxide, which will be released, and there will be a popping sound during the release process, which is also familiar to us. We can roughly determine the degree of roasting of coffee beans by the popping sound. In addition, the content of fat will increase by more than 4%.

As soon as the coffee bean leaves the drum, it will fall into a sieve-like container, and air will blow up through the sieve hole, thus achieving the rapid cooling effect of the coffee bean.