Material composition of coffee crema｜Why does espresso have oil? What factors affect the oil richness of espresso?_Brewing Guides_FrontStreet Coffee

Just a few days ago, a customer came to FrontStreet Coffee's store in Dongshankou, Guangzhou to drink espresso. Before leaving, he said, "I really like your espresso. The oil is the richest I have ever seen!" It happened that a friend asked FrontStreet how to make the espresso richer in oil. Today Front Street is here to share his insights.

Espresso, as the name suggests, comes from Italy in Europe. The purpose of developing espresso is to improve the speed of making coffee. Initially, espresso refers to a way of making coffee, and espres means "quick", meaning that a cup of black coffee can be made in a very short time.

意式浓缩c9c

The golden layer of crema in espresso is called crema. In fact, it is not strict to call it grease, because this layer of golden crema is composed of coffee crema and carbon dioxide. When this layer of crema disintegrates and the carbon dioxide dissipates, the remaining thin reflective layer is the coffee creme.

However, sometimes due to some customary sayings, this layer of golden crema can also be called espresso crema. Now that we know the composition of crema, if we want to extract rich crema, we need to choose beans with rich oil and sufficient carbon dioxide when choosing coffee beans.

1884year, italianAngelo MoriondoDesigned the first espresso machine with two independent brewing boilers,1.5barThe pressure and steam make the extracted coffee liquid more viscous and taste richer than drip coffee. As coffee machines are continuously improved, factors such as water temperature and pressure are better controlled.1948A café owner in MilanAchille GaggiaInvented the lever-driven coffee machine, which can produce the grease we are talking about now through high pressure (crema). From then on,cremaIt is considered one of the indicators of espresso quality.spressoIt has become a special method of producing a cup of high-concentration coffee rich in oil through pressurization.

The richness of coffee bean oil mainly depends on the type of bean and the degree of roasting. Generally speaking, the fat of Robusta is richer than Arabica, but the flavor is not as good as Arabica. Therefore, Roman beans are usually blended with Arabica to achieve a balanced state. For example, Front Street's Front Street Commercial Blend Series contains 10% Robusta. beans, enhance the oil of coffee and balance the flavor of coffee; the oil performance of American Arabica will be better than that of Africa. For example, the Sunflower Warm Sun Blend used in the Front Street store contains 70% Honduran sherry coffee beans, which provides rich oil.

The roasting degree also affects the richness of the extracted oil. Generally, the darker the roasting degree, the better the expressiveness of the coffee oil. So in order to show good oils, espresso beans are usually medium-dark roasted. Some friends wanted to pursue the acidity of espresso, so they used some medium-light roasted coffee beans to extract espresso. Naturally, the performance in Crema was not that good.

Next is the carbon dioxide content, which to put it bluntly is freshness. Carbon dioxide is produced during roasting and will be slowly discharged from the beans over time. Generally, it takes about 45-60 days for Italian coffee beans to be completely discharged. The flavor of coffee beans that have completely discharged carbon dioxide is almost exhausted (that is, they are not fresh). The extracted coffee oil is thin and only has the bitter taste of the coffee itself. Some friends came to ask Front Street why there is no oil in the espresso extracted from Front Street. When asked about the roasting date of the coffee beans, they found that they were roasted half a year ago... If they are left for too long, the coffee will not even have aroma, let alone oil. This is why Front Street has always emphasized the importance of fresh roasting for many years.

Some friends also refuted it. I bought coffee beans roasted abroad, and there was still grease after more than half a year. First of all, coffee beans imported from abroad will use some technologies such as adding nitrogen to keep them fresh. However, after you open the package, those fresh-keeping techniques will no longer work. After 2 months, they still have no flavor.

意式浓缩油脂9e540

Secondly, it does not mean that the fresher the Italian coffee beans are, the better. If the beans are not raised for 7-12 days, the rich carbon dioxide in the coffee beans will be pressed into the oil, forming a very rich crema. However, these cremas are very rough and unstable, and will break down quickly, and the flavor of the coffee will be relatively weak. Some friends just bought espresso coffee beans and asked Front Street why the flavor of the coffee was different from before. Front Street asked him to grow the beans for five days before trying them. After five days, he said that the taste was the same as before.

意式咖啡4

After choosing the right coffee beans, the rest is the problem of extraction. If you want to extract rich golden yellow oil, the extraction pressure should be maintained at 9 Bar. It is difficult for some small household machines that use vibration pumps to stabilize the pressure during the entire extraction process, which is also the reason why the oil is not rich.

With sufficient hardware support, it comes to the extraction method, such as powder-to-liquid ratio. Some friends think that if you want richer oil, you should extract more coffee liquid, and then the oil will increase. But if you observe the process of the coffee liquid coming out, you should find that it is brown-black at first, then brown-yellow, then golden-yellow, and finally yellow-white.

This is the process of coffee crema changing from strong to light. As you get to the later stages, the fat will become thinner and the color will become lighter, which will affect the overall quality of the espresso. The ratio of espresso powder and liquid in Front Street is usually between 1:1.8-2, and rarely exceeds 1:2. For example, the parameters debugged today are 20 grams of coffee powder and 30 seconds to extract 40 grams of coffee liquid.

You can now buy the above coffee beans online at the Taobao store “FrontStreet Coffee” (前街咖啡). FrontStreet Coffee is a long-established specialty coffee roaster in Guangzhou, China, and its Guangzhou retail shop sells coffee beans only. The shop carries dozens of coffee beans from different origins around the world, including carefully selected single-origin beans for V60 pour-over and espresso. Guangzhou’s FrontStreet Coffee shop is recommended by many coffee lovers.

The FrontStreet 2013 Yunnan coffee beans sold in the store come from the Typica variety grown at FrontStreet Coffee’s own plantation in Yunnan. The name comes from the year the brand and the plantation were founded. You can buy these beans from China’s Yunnan origin at the Guangzhou shop and at FrontStreet’s Taobao store.

FrontStreet coffee beans are freshly roasted within 5 days and deliver consistently excellent quality and great value. Orders placed before 17:00 are shipped the same day, and most areas within Guangdong Province receive them the next day.

FrontStreet Coffee Taobao store: https://qianjiecoffee.taobao.com
Or search for “前街咖啡” (FrontStreet Coffee) on Taobao
Important Notice: FrontStreet Coffee has moved to a new address: 315, Donghua East Road, Guangzhou (coffee beans only)
Tel: 020 38364473

Material composition of coffee crema｜Why does espresso have oil? What factors affect the oil richness of espresso?

Subscribe to Front Street Updates