How to maintain the freshness of coffee in hoppers?

In many cafés, hotel lobbies, or coworking spaces, hoppers full to the brim with coffee beans to eye-catching sight, but how to maintain the freshness of coffee beans in hoppers?

1. Reduce the number of beans that are put in at any one time and avoid leaving them there overnight.

2. Use sealed hoppers to reduce air ingress into the space.
Reason: Because the air contains bacteria or fungi and moisture, the coffee beans absorb moisture and will be damp. In the presence of air and moisture, the decomposition rate of bacteria or fungi on coffee beans will be accelerated, affecting the flavor of coffee beans.

3. Use hoppers with shading function:
The coffee machine hopper is mainly made of glass and plastic, and colorants can be added to them, and consumers can buy colored hoppers. Because the light can trigger and accelerate the decomposition and oxidation of coffee ingredients. Any kind of light source will lead to the freshness of coffee beans and a decrease in flavor stability.

4. Increase the thickness of glass or plastic.

5. Film: Similar to car film, stick a special shading film on the hopper.

6. Periodically clean oil stains from the hopper with a damp cloth.
Reason: Oils (lipids) account for about 15-18% of the dry weight of coffee beans. They are wrapped by independent films and distributed in the cytoplasm of coffee beans. As the roasting deepens, the cell structure is broken and gradually migrates to the surface of coffee beans. A layer of oil film is formed, especially the deeper the baking degree, the more oil will be produced, so oil production is a normal phenomenon.

However, the oil does not mean it is not fresh, and the dry surface does not mean it is fresh. Some beans will emit a large amount of gas when they are very fresh and will bring out oil. After the stable period, the oil will be reabsorbed by the beans for oxidation. There will be heavy rancid flavors.

Author: Lillian Mao

Date: 2022.1.6