Experienced friends know that there are many factors that affect the taste of cold brew coffee. Among them, the most influential ones are the selection of coffee beans, grinding degree, powder-to-water ratio, and soaking time, followed by some small production skills, such as sufficient stirring, ensuring that the container is clean, water quality, etc., which will more or less change the final taste of the coffee.
But in fact, there is another detail that has also attracted the attention of many friends: Although I have used the parameters provided by Front Street in the tutorial, there is always a layer of oil floating on the cold brew I made, so I wonder if the coffee is broken, or the equipment is not cleaned.
Before finding out the reason, Front Street believes it is necessary to first find out what the "oil" on the coffee is.
Many people know that freshly made espresso will have a denseCrema, it is not only the source of coffee aroma, but also a symbol of the freshness of coffee beans. In terms of ingredients, Crema is a manifestation of carbon dioxide wrapped in fat, mainly coming from the water-soluble fat in the coffee beans. When the foam group completely dissipates, we can see a layer of floating matter on the coffee liquid, and this is the realcoffee crema。
In fact, coffee oil can also be found in other normal pressure extractions. For example, when we use a French press to extract medium-dark roasted coffee, the oil will seep out due to the large gaps in the metal filter.Let the surface of the coffee liquid have a layer of "oil sheen", andSome extremely fine powder will also run into the water, making it taste particularly "turbid".
As for cold brewing, even though the whole process is soaked in a low-temperature environment, the water-soluble fat in the coffee will still be released into the coffee like hot extraction, but at a slower speed, and the little bits of oil are the result of the condensation of coffee oil.
Compared with other extraction methods, cold brewing has few requirements on the container. It can be specializedcold brew pot, it can be a clean sealed can at home, or a beverage bottle that has been drunk and cleaned. In short, as long as it is hygienic and has no odor, and can ensure that the airtight container is isolated from outside air, it can be used as a "cold brew pot".
Similarly, there are many options for filtering coffee grounds, such as the built-in filter in the cold brew pot, metal filter cup, filter paper for hand brewing, flannel, and the mesh of the ear-hanging inner bag are all commonly used filtering equipment. The materials are different, the structure and size of the filter holes are different, and the particulate matter that can be effectively blocked is naturally different. And if you want to remove the particles from your coffee,Condensed grease, it is necessary to choose an appliance with better filterability.
Front Street found that some friends thought filtering was too troublesome, so for the sake of convenience, they directly poured the upper part of the cold brew after brewing it.coffee liquidPour it out and drink it. In fact, this method will make the coffee contain a lot of condensed oil, which will not only taste dull, but also taste gritty and accompanied by many dust-like floating particles. Generally, the taste will not be very good.
For example, the cold brew pot often used in Front Street stores has a built-in filter with a mesh size of 300, which is relatively fine. It is currently used to soak fruity coffee beans.cherry tomatoesWhen roasting, because the roasting is shallow, a finer grinding degree will be used (China No. 20 powder sieve screening rate is 80%), which corresponds to the EK43s grinder scale of 9.5 grids/C40 grinder scale of 22 grids.
When the filter element is removed after 10 hours of extraction, the coffee liquid that is poured out still has a lot of very fine powder remaining in it. If it is not filtered again, not only will there be a layer of oil on the surface of the liquid, but the coffee will taste obviously rough. There are even powder residues visible to the naked eye at the bottom of the cup after drinking.
Therefore, in order to make the cold brew taste better, Front Street will use the best filter paper to "sift" the coffee again to remove most of the condensed oil and ultra-fine powder particles. At the same time, the filtered cold brew coffee liquid will be sealed and refrigerated in the refrigerator for 3 to 4 hours until the flavor substances are further precipitated and fermented. This can make the cherry tomato cold brew juice fuller and more acidic.
In addition to filtration, the cleaning of utensils cannot be ignored. Many friends do not spend too much time cleaning the cold brew pot after using it, but simply rinse it with tap water. Over time, the condensed coffee oil will stick to the filter, forming a "gas consumption smell". If the frequency of use is high, Front Street recommends dismantling it regularly and scrubbing it carefully with detergent. This can not only remove residual oil, but also avoid aging of the filter.
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
