How to Judge the Quality of Coffee Beans? How to Determine if Coffee Beans Are Fresh?

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Determining the Quality of Coffee Beans

Quality roasted beans have no color spots, with even heat distribution from exterior to interior. They should contain virtually no defective beans, be completely roasted, and show good expansion. They should possess a beautiful color and luster formed by appropriate heat—only then can they be called quality roasted beans. Coffee beans enveloped in smoke during the roasting process will have black fine particles attached to their surface, causing them to appear blackened and dirty, which can be identified by their appearance.

Methods for Judging Roasting Quality

In addition to the above-mentioned appearance-based methods, you can also cut coffee beans with fingernails or a knife to observe their cross-section, or grind a small amount of coffee beans and spread them out to see if their color is uniform. Another method is to take two or three coffee beans and bite them—if they are very crispy and crack apart with a bite, have good texture, feel fresh in your mouth, and release a bitter taste with accompanying aroma that spreads across your tongue, they represent quality roasted beans. Additionally, you can check whether the aroma has diminished as a standard, because aroma is the life of coffee—meaning that however much the aroma decreases represents that much deterioration in quality.

Storage Considerations for Different Roast Levels

The shelf life of lightly roasted coffee beans is influenced by acid components. During storage, if freshness decreases and moisture is present, oxidation will produce strong, unpleasant flavors and odors, especially in new beans. For storing dark roasted coffee beans, special attention must be paid to smoky and burnt odors caused by improper heat, exhaust, or cooling. Additionally, greater attention must be paid to fats—dark roasted coffee beans will exude fats invisible on light roasted beans. As the storage period extends, sunlight and temperature will promote fat oxidation, creating characteristic odors. While sealed containers may be used to maintain coffee bean freshness, this will actually increase the temperature inside the container, creating a vicious cycle that accelerates deterioration. The resulting spoilage odors cannot escape due to the sealed container and will fill it, also strongly seeping back into the beans and exacerbating their deterioration.

Optimal Storage Methods

Based on the perspective of oxidation caused by air contact, vacuum packaging or filling with inert gas is generally used. However, regardless of how good the packaging is, you must also ensure the container with fresh coffee beans is properly sealed, store it in a dark place according to sunlight and temperature conditions, and strictly observe the storage period—only then will storage be completely problem-free.

Freshness Timeline

The freshness of coffee beans is calculated from the time they are roasted.

Freshly roasted coffee beans will begin degassing, continuing for approximately 3-5 days. After the gas is completely released (about one week), the freshness of the coffee beans will begin to decline over time.

Indicators of Coffee Freshness

1. Oil Production: Light to medium roast beans show no visible oil; the darker the roast, the more oil appears. Therefore, if you see oil on dark roasted beans, remain calm—this is normal. However, if you see oil on light roasted beans, it's recommended not to drink them.
2. Aroma: Freshly roasted coffee beans will have a rich, intense aroma.
3. Foam: Fresh coffee beans still contain some unreleased gas, so the expansion of filter bags is not due to added nitrogen but rather the packaging of fresh beans.

When hot water is poured over ground coffee, foam will form on the surface. Coffee beans, like breathing, will produce subsequent bubbles and oils. This is also why there is a blooming step—blooming accelerates the degassing of coffee grounds and reduces the occurrence of channeling.

FrontStreet Coffee's coffee bean bags are packaged with one-way degassing valves designed to expel air from inside the bag. Since fresh beans release carbon dioxide, this expels gas from inside the bag, maintaining bean freshness and reducing oxidation.

Important Notice :

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