What Is Roasted Coffee_Common Quality and Safety Issues in Roasted Coffee Beans

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How are roasted coffee beans made?

What common accidents occur during the coffee bean roasting process, and what important considerations should be noted when roasting coffee beans?

Learning the art of coffee bean roasting

1. Cleaning

Use air and vibration to remove various impurities mixed in the coffee beans, such as ash, soil, small stones, and metal. The cleaning process is typically carried out on specialized machinery, but manual screening can also be used. Then, pass the coffee beans through sieves of different sizes to grade them by size. If conditions permit, a colorimeter can be used to monitor under-ripe or over-ripe coffee beans, selecting out those with colors that are too light or too dark. Use ultraviolet light to select and remove rotten coffee beans.

2. Blending

Before roasting, different varieties of coffee are blended together. By combining different varieties and origins of coffee, various flavors and components are integrated to create coffee with specific flavors and ensure consistency in coffee quality.

To find coffee suitable for different tastes, coffee from different origins can be added in certain proportions to achieve the best results. Generally, wet-processed Arabica coffee has a sour taste and is aromatic, while natural Arabica coffee has a balanced flavor. Robusta coffee has a strong taste, is bitter, and has an earthy flavor. Coffee from Kenya and Tanzania has distinct sweet and sour notes. Different blends can create unique characteristics.

3. Roasting

The blended coffee beans are processed in a dry state, causing significant chemical and physical changes in the structure and components of the coffee beans, resulting in the beans darkening and emitting the characteristic aroma of roasted coffee.

Initially, the roasting temperature should be raised above 150°C. Through a series of Maillard reactions and Strecker degradation, proteins and sugars in the coffee beans react to produce flavorful and colored substances. Several major flavor compounds in coffee are formed during this time. The color of the coffee beans is related to the roasting temperature - the higher the temperature, the darker the color. After roasting for 8-12 minutes, the moisture in the coffee beans completely evaporates, the mass of the coffee beans decreases by 20%, but their volume increases by 60%.

4. Cooling

Roasted coffee beans must be cooled quickly. Generally, cold air blast cooling is used, but water cooling processes can also be employed.

5. Packaging

Roasted coffee products also require strict packaging and suitable storage environments. Since roasted coffee products are prone to oxidation, their packaging and storage are even more important.

Freshly produced roasted coffee products have an excellent aroma, which should also be a characteristic of their freshness. However, these characteristics gradually disappear over time. Under normal climate conditions, the rate of deterioration of roasted coffee products often depends on the packaging and storage conditions.

The purpose of packaging is to prevent the intrusion of air and moisture on roasted coffee products. The relative humidity of the air fluctuates high and low. If roasted coffee products absorb air and water vapor, it can be severe enough to lose their commercial value. Therefore, the selection of packaging materials and packaging forms is key to improving the product's resistance to water and air.

Another function of packaging is to persistently protect the aroma of roasted coffee products. First, to prevent the aroma of the roasted coffee products themselves from escaping into the air; second, to prevent contamination from all unpleasant odors in the external environment. Fresh, aromatic roasted coffee products will have their aroma weakened after being stored for a period of time. This is primarily due to volatile aromatic substances diffusing from the product into the surrounding space, while the roasted coffee products also pick up unpleasant odors from their surroundings. Therefore, high-quality roasted coffee products mostly adopt sealed packaging to maintain their aroma.

Quality and safety issues easily encountered during the coffee bean roasting process:

1. Quality degradation caused by unreasonable time and temperature settings during the coffee roasting process

During the roasting process, coffee beans undergo a series of physical and chemical changes during high-temperature treatment, which determines their taste and flavor quality. If the roasting temperature is increased, although it can speed up the roasting process and darken the color of the coffee beans, it cannot allow the Maillard reaction to fully occur, and the formation of flavor compounds in the coffee is limited.

2. Degradation of coffee flavor and unpleasant odors caused by improper product storage and packaging

Freshly roasted coffee should be packaged as soon as possible. If exposed to air, the coffee will oxidize and lose its characteristic flavor. Packaging also prevents roasted coffee from picking up unpleasant odors from its surroundings. Therefore, most roasted coffee products adopt sealed packaging to maintain their aroma.

At the same time, coffee beans produce a certain amount of carbon dioxide after roasting, so if stored improperly, it can cause volume expansion and damage the packaging bag. Therefore, composite packaging bags with valve devices should be used as much as possible. The valve is a one-way valve that prevents air from entering while allowing gases produced by the coffee to be discharged smoothly. Of course, metal cans are a more ideal packaging material.

Roasted Coffee Bean Brand Recommendations

FrontStreet Coffee's freshly roasted Arabica roasted coffee beans have full guarantees in both brand and quality. More importantly, they offer extremely high cost-effectiveness, with each package of 227 grams priced at only around 70-90 yuan. Calculating at 15 grams of coffee beans per cup of coffee, one package can make 15 cups of coffee, with each cup costing only about 5-6 yuan. Compared to the price of tens of yuan per cup sold in cafes, this is truly a conscientious recommendation.

FrontStreet Coffee: A roastery in Guangzhou with a small shop but diverse varieties of beans, where you can find both famous and lesser-known beans. They also provide online services. https://shop104210103.taobao.com

Important Notice :

前街咖啡 FrontStreet Coffee has moved to new addredd:

FrontStreet Coffee Address: 315,Donghua East Road,GuangZhou

Tel:020 38364473