What is the effect of coffee freshness on coffee extraction?

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For most coffees, exhaust reactions occur during the 4-14 days after roasting. As we all know, to make delicious coffee, it is best to use fresh, high-quality coffee beans. But what is the definition of "fresh coffee"? More importantly, how to extract the good taste of coffee?

In order to find the flavor peak of freshly roasted coffee, you need to balance two important factors:

1. The loss of aromatic substances

two。 Production of carbon dioxide

Under different circumstances, "fresh coffee" can have a completely different meaning. Usually, it means a roaster's assessment of the best taste of coffee. But that doesn't mean the coffee will be at its best as soon as it comes out of the roaster. In order to better understand "fresh" and "flavor", it is more important to consider the process of coffee flavor formation.

The freshness of coffee is a fickle thing. In this industry, we all know that ultra-fresh coffee is not good. Because beans need time to release potential carbon dioxide, carbon dioxide is converted into carbonic acid in coffee, bringing astringency to coffee.

Beans baked in a low oxygen environment, coupled with bags filled with nitrogen and sealed, contain less than 1% of the residual oxygen, and are equipped with an one-way exhaust valve that allows carbon dioxide to be discharged during coffee exhaust. Such coffee beans can prolong the taste period. There was a test that compared the beans baked 90 days ago with those baked 24 hours ago, and found that although the two beans could feel the difference in flavor, there was only a small difference in aroma, flavor, acidity and sweetness, which could remain the same.

Therefore, when coffee is stored in an environment containing 2% oxygen, there is a slight difference in aroma and flavor degradation, while when coffee is stored in 20% 21% oxygen (normal air), the difference is very significant.

For all coffee beans used to make espresso, we recommend that they be used at least 5 days after baking. There are some internal standards: espresso extraction begins 7-11 days after baking, hand-brewed coffee extraction begins 4-7 days after baking, and cold extraction begins 10-14 days after baking. The "honey period" of each different coffee bean also depends on the roasting degree of coffee, the density of coffee beans, the method of treatment,