Just a few days ago, a customer came to the store to drink espresso, and before leaving, he said, "I really like your concentrate, the oil is the richest I have ever seen!" "It just so happened that a friend asked Qianjie how the espresso could be made richer in oil. Today, Front Street is here to share the insights of Front Street.
The golden grease of espresso is called crema, which is actually not very strict to say that it is grease, because this golden layer of crema is composed of coffee grease and carbon dioxide. When the crema disintegrates, the carbon dioxide dissipates, and the thin reflective layer is the coffee grease.
However, sometimes because of some idioms, it is also possible to call this layer of golden crema espresso grease. Now that we know the composition of Crema, if we want to extract a rich amount of Crema, we need to choose beans that are rich in fat and carbon dioxide in the choice of coffee beans.
The richness of coffee bean oil is mainlyBean seedsandRoast degree。Generally speaking, Robusta's fat will be richer than Arabica, but the flavor is not so good compared to Arabica, so Luo beans and Arabica are generally blended together to achieve a balanced state, such as the commercial blend series of Front Street, which contains 10% Luo beans to enhance the oil of coffee and balance the flavor of coffee; The oil performance of Arabica in the Americas will be better than that of Africa, such as the sunflower warm sun blend used in the front street store, which contains 70% Honduran sherry coffee beans, providing rich oil.
Roast also affects the richness of the oil extracted, and generally the darker the roast, the better the expressiveness of the coffee grease. So in order to show good oil, espresso beans are usually medium to dark roast. Some friends want to pursue the acidity of espresso and use some medium and light roasted coffee beans to extract espresso, and the performance in Crema is naturally not so good.
Next is the amount of carbon dioxide, to put it bluntlyFreshness。Carbon dioxide is produced during roasting and is slowly expelled over time, and it takes about 45-60 days for espresso beans to be fully discharged. The flavor of the coffee beans that have completely emitted carbon dioxide is almost exhausted (that is, it is not fresh), and the extracted coffee fat is thin and only the bitterness of the coffee itself. Some friends came to ask Qianjie why the espresso extracted had no oil, and asked the coffee beans roasting date and the ...... roasted half a year ago
There are also some friends who come to refute that I have bought coffee beans roasted abroad, and there is still oil after most of the year. First of all, imported coffee beans will use some technologies such as adding nitrogen to keep them fresh, but after you open them, those preservation techniques will not work, and after 2 months, they will still have no flavor.
Secondly, it is not that the fresher the espresso beans, the better, if they do not go through the 7-12 days of bean rearing period, the rich carbon dioxide in the coffee beans will be pressed into the oil to form a very rich crema, but these crema are very coarse, unstable, will quickly break and decompose, and the flavor of the coffee will be relatively weak. Some friends just bought espresso beans and asked Qianjie, why the coffee flavor is different from before, Qianjie asked him to raise beans for 5 days and then try it, 5 days later he said that it was the original taste.
After choosing the right coffee beans, all that remains is the matter of extraction, wanting to extract the rich cremaExtraction pressureTo maintain it at 9 bar, it is difficult for some small household machines that use vibrating pumps to stabilize the pressure during the extraction process, which is also the reason why Crema is not abundant.
Once you have enough hardware support, that isExtraction methodFor example, some friends will think that if you want to be richer in oil, you should extract more coffee liquid, so that the oil will also increase. But if you look at the process of coffee coming out, you should see that it is brownish-black at first, then brownish-yellow, then golden-yellow, and finally yellowish-white. This is the process by which coffee crema goes from strong to light. The later you go, the thinner the quality of the crema is, and the lighter the color, which in turn affects the overall quality of the crema. Front Street's espresso powder ratio is usually 1:18-2, rarely more than 1:2 ratio.
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