A good "fermentation" process is a great blessing for commercial coffee beans!

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For coffee people, yeast and bacteria convert sugar into compounds such as energy and flavor. Fermentation occurs in all three treatments of coffee and affects its flavor. Bad fermentation leads to coffee mildew, but if it is well used, fermentation can bring a flavor that is loved by consumers and different from others.

Fermentation is the process of decomposing sugar and starch after microorganisms such as yeast and bacteria encounter nutrients. For coffee people, yeast and bacteria convert sugar into compounds such as energy and flavor, and produce good flavor with the slow rise of temperature and the passage of time.

Fermentation occurs in all three treatments of coffee, and has an unimaginable effect on flavor and touch-poor fermentation leads to coffee mildew and even irritating chemical taste, which is why handlers need to monitor the whole process. and make timely adjustments according to the actual situation.

An important process in coffee processing: fermentation

After the fruit begins to ferment in the fermentation tank, the slime layer on the endocarp acts with microorganisms, the temperature in the tank will gradually increase, and the fermentation will accelerate. Attention must be paid to the rate at which the temperature in the environment rises and the pH value decreases (such as the rapid decline of pH, indicating that acidification is too fast), both of which can lead to unpleasant taste, such as metal or acetic acid or even rough touch. On the contrary, if the process is too slow or the fermentation is not completely stopped, it will also lead to abnormal flavor and quality.

Fermentation time ranges from 8 hours to nearly 72 hours, mainly depending on the temperature of the environment (high altitude mountain areas are often more than 2 days, because the environment temperature is low). Higher ambient temperature or thicker pectin mucus layer will accelerate fermentation. The time to stop fermentation involves the flavor and quality of coffee, and key factors include pH value, acidity, sugar content, and residues left on the inner pericarp.

Several other studies have shown that the addition of certain types of enzymes, yeast or hot water can speed up sun fermentation. These methods are generally used before the pulp is removed by machines, which can effectively reduce water consumption and protect the fermentation environment. Although some experiments have shown that enzymes and yeast can change the content of volatile and non-volatile substances, it is difficult to achieve commercial application.

Fermentation greatly affects the flavor of coffee beans.

Good fermentation can ensure that the high-quality original flavor can be presented, and the process of adding commercial yeast can be well controlled and can be flavor-enhanced, especially for commercial coffee with flat flavor. The current methods of controlling fermentation can provide more prominent flavor or non-original flavor according to customer demand, usually focusing on improving sweetness, acidity and touch, such as fruit acid of specific fruit, or caramel, chocolate and other flavors.

However, if the fermentation time is too long, it may lead to a sharp decline in flavor quality, acidity, alcohol thickness and sweetness. Coffee farmers should receive some training on quality analysis if they want to understand the fermentation process and make proper judgments. for example, cup testing can evaluate the impact of the fermentation process and adjust it in time.

Bean hunters can help identify several control points for coffee farmers on fermentation:

The equipment must be clean.

Second, record the relevant data during and after fermentation in order to track, control and repeat the fermentation process. These values include sugar content, pH value, fermentation time, temperature and so on.

Third, carry on the cup test finally. The more information you have, the easier it is to use fermentation to get consistent high-quality coffee.

If not handled properly, fermentation is likely to be a disaster for coffee bean processors, but if used properly, fermentation can bring a distinctive flavor that is loved by consumers.

Source: bean hunter 2, African curiosity of the International Coffee Review.

Written by Xu Baolin

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