The most effective method for judging the basic knowledge and freshness of coffee beans

The "light baked beans" that are not fresh and have a light brown appearance are dry and will not produce oil after baking. About five days after it comes out of the oven (it may be shortened to one or two days at the height of summer), the phenomenon of "spot oil" begins to appear (dotted oil droplets appear on one side of the coffee bean) Please note: a little "spot oil" does not mean it is not fresh. sometimes the flavor of light-roasted coffee beans is at its peak. Continue to put, more than two kilos out of the oven, the surface of shallow baked beans gradually covered with a uniform, thin and bright oil, the smell is not sweet, but with fuel consumption, at this time, the flavor of "shallow baked beans" has gone downhill and should be avoided.) Fresh deep-baked beans, which are dark brown in appearance, show a slightly glossy appearance after baking, and begin to produce a large amount of oil on the surface from the first day to the second day. The bright-looking "deep-baked beans" not only do not mean that they are not fresh, but on the contrary, the glossy appearance will gradually dry out after three times of cooking, and eventually become dry-looking off-flavoured beans. Therefore, if you see coffee beans that are dry but dark brown in appearance, please pay special attention to whether they are marked with a baking date and are most likely to be stale beans that have gone bad. The method of judging the freshness of coffee beans, even if they are no longer fresh, the appearance of "shallowly roasted beans" with oily appearance will gradually dry out after a long time (such as three months), and finally return to the dry and unoily appearance. Thus it can be seen that the appearance of oil is only a reference to judge the freshness of coffee beans, not absolutely. How should we judge the freshness of coffee beans? First of all, please choose from the professional coffee roasters who have clearly marked date, brand reputation and emphasize fresh roasting. In addition, excellent coffee bags are usually designed with a "one-way exhaust valve" (a button-shaped hole in the top of the coffee bag) for coffee beans to release naturally occurring carbon dioxide. Point the one-way exhaust valve at the nose, gently squeeze the coffee bag and smell the gas. If it is a charming and fragrant coffee aroma, the freshness will not be a problem. On the contrary, if it does not smell strong enough, or even smells of smelly oil, it means that this bag of coffee has already gone bad and should be avoided. Conclusion-"the appearance of freshly baked shallow baked beans should be dry and oil-free, and the surface of freshly baked deep baked beans should be shiny" is the correct concept that we should understand. When buying coffee beans, the appearance of oil, no oil is a reference index to judge the freshness, but not absolutely. It is the best policy to choose reputable merchants and buy them with wide eyes.