Baking and mixing of high-quality coffee beans

When there are good coffee beans, the most important step to make them high-quality coffee is roasting and mixing.

In general, raw beans have a pungent earthy smell, and after the correct baking "fragrance", it will emit a strong aroma. In fact, raw beans contain 700 to 800 aromatic ingredients, which must be "awakened" by baking.

First of all, after baking more than 200℃, the water begins to evaporate, the volume expands by more than 50 per cent, and the weight is reduced by 10 per cent and 25 per cent depending on the degree of baking. The deeper the baking, the more weight loss.

In addition, raw beans release carbon dioxide during baking and will continue to exhaust within 30 days after baking. What is interesting is that this exhaust contributes to the preservation of coffee beans, because oxygen molecules are not easy to invade in this process, and the oxidation that destroys the flavor of coffee cannot be carried out. Then the exhaust gradually slows down after 7 days of baking, the oxygen molecules are easily attached to the bean table, and the coffee flavor is easy to decline, which is an important reason why coffee beans are best used up within a week after opening.

Professional coffee is generally roasted in small batches. The most common methods are: tympanic baking and hot air baking.

The drum roaster puts the coffee beans in a rotating vat and burns gas or wood to bake them. When the desired baking degree is reached, the coffee beans can be poured into a cooling funnel to prevent overbaking.

Figure: tympanic baking method

Hot air roaster, also known as fluidization air roaster, roasts coffee beans by rolling them in hot air. Most raw coffee beans are roasted at a temperature of nearly 400 degrees.

The roasting degree is roughly divided into shallow roasting, medium roasting and deep roasting, but there is no unified standard in the coffee industry. American baking degree classification is used at most in the industry, as shown in the following table:

Picture: American roasting grade of coffee beans

There are more than 100 coffee producing areas in the world, and their coffee beans have their own characteristics. The mixing of coffee beans is to balance the flavor of coffee in order to create an unparalleled delicacy.

A single coffee bean generally lacks the complex flavor necessary to make a delicious cup of coffee. Many blends contain three to seven different types of coffee beans. In Italy, for example, some Robster beans are added to mixed coffee to increase the complexity of its fat, caffeine and coffee flavor.

Roasters understand the characteristics of each kind of coffee beans and mix them artistically to create a desired new flavor. It is said that the knowledge of roasters mixing coffee beans is the highest industry secret.

But as for baking or mixing first, this has always been a controversial issue among bakers. Generally speaking, each product is roasted first and then mixed, which will maximize the different flavor characteristics of each kind of coffee and produce the best effect. The classic Blaser coffee beans launched by the Swiss coffee maker use this way to bring you the most delicious coffee.

Photo: Swiss Blaser Classic Coffee beans