Is Italian hand-brewed coffee beans producing oil good or bad/Can you still drink it? Why does deep-roasted coffee produce oil faster than lightly roasted coffee?

As we all know, Qianjie sells coffee beans, so it can often receive various feedback about coffee beans, which is also the main source of Qianjie's content. What Qianjie wants to share today, as the title suggests, is about the oil production of coffee beans. Because Qianjie found that many friends didn't understand why coffee beans produced oil, and didn't know whether the coffee beans produced oil was good or bad, customer service often received the following questions: "Why did the coffee beans produced oil only two days after they were bought? Are the beans stale? "" Why haven't the coffee beans come out after being left for more than half a month? Are the beans undercooked? "You can see that different friends have different understandings of the oil production of coffee beans. Some friends think that oil production is proof of high-quality coffee beans, so the sooner the oil is produced, the better; some friends think that oil production is a sign of obsolescence of coffee beans, and only coffee beans that have been aged for a long time will produce oil. But in fact, the production of oil from coffee beans has nothing to do with the quality of coffee beans. Why? Because it is determined by the degree of roasting of the coffee beans.

Green coffee beans themselves contain a lot of lipids, which are an important source of coffee aroma and mellow taste. Its content usually accounts for about 10% to 18% of the dry weight of coffee beans, and the specific proportion is mainly affected by the variety. Generally speaking, the oil content of Arabica species is generally higher than that of Robusta species, about 14% to 18%, while the lipid content of Robusta species is 9% to 12%. Because of this, the aroma of coffee grown in Arabica will be better than that grown in Robusta (one of the reasons).

But because of this, the Italian concentrated Crema extracted with Arabica will not be as rich as Robsta's when the degree of baking is equal. The specific explanation of Qianjie has been shared in previous articles, so I won't introduce it more here. Then what everyone needs to know is that although the amount of fat in coffee is determined by the variety of coffee beans, the amount of oil produced by coffee beans is not controlled by the variety. Because as Qianjie mentioned earlier, this is mainly determined by the degree of roasting of the coffee beans.

We all know that the degree of roasting of coffee beans affects many aspects, such as carbon dioxide content, expansion rate, density, coffee taste, aroma, etc. These are all contents that Qian Jie has shared in previous articles. In addition, there is the oil yield rate of coffee beans. The deeper the coffee beans are roasted, the faster the oil will emerge, and vice versa. This is the fundamental reason why the oil extraction time varies between different coffee beans.

Why does the degree of roasting affect the oil yield rate of coffee beans? Because roasting affects the structure of coffee beans. Under normal circumstances, the deeper the coffee beans are roasted, the larger the beans will expand, and the cell wall will break and the structure will become looser, so the oil in the coffee beans will more easily migrate to the surface; conversely, When the coffee beans are roasted more lightly, the oil migration speed is very slow because the bean body expansion coefficient is small and the cell structure is tight. This gap is still very obvious! Take Qianjie as an example. Qianjie Esseau in the Qianjie bean list is a medium and light roasted coffee bean baked during a burst period. Because the baking is light, it produces oil very slowly. One month after the baking is completed, the bean surface only becomes more "moist" and no oil stains are seen. Its flavor is expressed as strawberry, mango, floral fragrance, and guava.

The other bean in the Qianjie Bean List-Qianjie Indonesia PWN Golden Mantonin is a deep-roasted coffee bean baked after the second explosion. Because the baking is deep, it produces oil very quickly. It has become oily from the second day after the baking is completed. Then, as the standing time increases, the amount of oil produced becomes more and more. Its flavor is expressed as chocolate, caramel, nuts, and spices.

Of course, this is not the fastest. If it is coffee beans that are roasted deeper, then we can already see the oily shine on the bean surface the moment the coffee beans are roasted and baked. So we can know that the oil yield rate of coffee beans is mainly affected by the degree of roasting. Oil production does not mean deterioration, it is just a normal physical phenomenon. When stored properly, the overflow of oil will even bring us a richer aroma, but only if stored properly, coffee beans with oil will be more likely to undergo qualitative changes than coffee beans without oil.

Therefore, if you buy coffee beans that are roasted deeply and then oily, please remember to store them well. The only way to extend the taste period of the coffee beans and ensure that the coffee beans will not be affected by qualitative changes. The taste of coffee.

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