There will be a layer of "grease" on the surface of coffee beans. Many coffee lovers call it coffee oil. In fact, this oily substance is not coffee oil, so
These "oils" evenly distributed on the surface of coffee beans are actually not "grease", but a kind of water-soluble organic matter that looks like grease. "Coffee oil" itself contains a lot of coffee aroma components, which can be dissolved in water, so there will be no greasy oil floating on the surface of your brewed coffee, so
Oil-producing coffee beans can basically be determined as stale coffee beans. Of course, in addition to deep roasted fresh coffee beans, there are two main reasons for producing oil coffee beans:
Stale shallow baked beans B fresh deep baked beans.
Fresh shallow baked beans are baked with shallow fire, and the appearance is light earth color. After baking, the appearance is dry and there will be no oil. About six days after baking, some oil began to appear (some oil appeared on one side of coffee beans).
Drop), at this time, the coffee beans have not changed flavor, but the quality will be correspondingly reduced compared with the freshly baked coffee beans. Of course, lightly roasted coffee beans are a bit oily, which is sometimes a sign that the flavor has reached its peak.
When coffee beans are roasted for more than two weeks, the surface of lightly roasted coffee beans gradually appears bright luster. At this time, it is difficult to guarantee the flavor and quality of shallow baked beans, so you should avoid buying them.
Fresh deep-baked beans are baked with deep fire, and the appearance of deep-baked beans is dark earth color. After baking, the appearance was slightly shiny, and a large amount of grease began to appear on the surface from the second day to the fifth day. Deep baked beans with shiny surface do not mean they are not fresh. On the contrary, deeply baked beans, after three weeks of baking, will gradually dry up and eventually become stale beans with dry surfaces.