As one of the representatives of iced coffee, cold brew is usually made with normal temperature water (about 20-30℃). However, due to the low extraction efficiency, it needs to be soaked for a long time to obtain more flavor substances to highlight the sweetness and body of the coffee.
Experienced friends all know that making a pot (cup) of cold brew can take anywhere from 5 to 6 hours to nearly a whole day. Compared with other coffee methods, cold brew is obviously a type of "slow work, careful work". Based on this, some people have proposed using warm water to soak coffee powder to shorten the production time of cold brew.
With a skeptical attitude, Front Street checked some articles and found that using warm water to brew cold brew coffee is nothing new. Many people have done related experiments and said that the coffee produced in this way will be sweeter. So, today we will also discuss this gameplay.
The difference between cold water brewing coffee and warm water brewing coffee
Essentially, compared with most high-temperature extraction methods, long-term cold soaking allows low-temperature extraction to more fully release the sweet and sour substances in the small molecules in the coffee particles. At the same time, with the help of the refrigerator, it will further suppress the appearance of bitter substances, thereby giving the coffee a better taste.
coffee science foundationA research report on cold-brew coffee jointly published by the Specialty Coffee Association analyzed that coffee extracted by low-temperature immersion will have more floral and fruity aromas and less bitter, sour and defective flavors than high-temperature extraction.
For the same coffee beans, when extracted using the same weight, proportion, and grinding degree, the rates at which various chemicals in the coffee dissolve into hot and cold water are different. According to research statistics, different sensory attributes have significant changes with extraction temperature. Among these four attributes, bitterness, sourness, and rubbery taste were significantly higher in coffee extracted at high temperature than at low temperature, while floral aroma was higher in coffee extracted at lower temperature.
During the high-temperature extraction process, the tannic acid in coffee will be decomposed into pyroic acid preferentially, and various fatty acids will dissolve more and faster in hot water, making it more likely to be accompanied by bitterness and sourness. Under low-temperature extraction conditions, as time goes by, the types of sour compounds will gradually decrease, so the sour and bitter taste of cold-brewed coffee will be greatly reduced. At the same time, the refrigeration environment also weakens the volatilization of the coffee aroma, allowing more aromas to be "locked" in the coffee.
When we use lukewarm warm water to extract coffee, it not only drives part of the substance to undergo thermal movement, allowing small molecule particles to be gradually released in a short period of time, but as the added water slowly warms up and cools down, the thermal movement of the molecules will prevent the coffee particles from clumping together, making subsequent coffee extraction more uniform and inhibiting the precipitation of bitter substances.
The operation of soaking in warm water and cold brewing
In this test, I used Front Street to brew cold brew coffee with warm water.Alida Carduai, a Panamanian coffee bean that has been dried in the anaerobic sun. It has a soft floral aroma, sweet orange and plum jam flavors, and a sweet and sour taste. It is more suitable for hand brewing and cold brewing. In addition, considering that the increase in temperature is easy to makeVery fine powderIf there is a chance of over-extraction, Front Street will adjust the grinding slightly to achieve a balance.
The specific extraction parameters are as follows:
Coffee powder: 30g
Grinding degree:EK43s-10 grids (75% screening rate of No. 20 screen, C40-26 grids)
Pink to water ratio: 1:11
Water temperature: 45℃
Prepare a clean container, pour the ground Alida coffee powder, then add 330ml of 45°C warm water, and stir thoroughly. After the coffee liquid has cooled down to 35-40°C, it can be sealed and placed in the refrigerator. After about 3 hours, take it out and stir again, then filter out the coffee grounds.
For comparison, Front Street brewed another pot of cold brew with room temperature water. The parameters are: 30g coffee powder, grinding degree EK43s-10 grid, powder-to-water ratio 1:11, and soaking time of 7 hours.
Under the same parameters, Alida's cold brew, which uses room temperature water + long-term low-temperature extraction, tastes like light floral, pineapple, orange, and light sweetness of black tea, accompanied by a slight sense of fermentation, with just the right balance;
The 40°C warm water + low temperature extraction for 3 hours showed an elegant bergamot and jam aroma, with a sweetness like brown sugar and peach in the mouth. Unfortunately, the flavor was weak and the aftertaste was short. Front Street speculated that the soluble substances were not matured enough. So Front Street sealed the coffee and put it in the refrigerator, refrigerated it for 3 hours and tasted it again. Sure enough, all the flavors were expressed more fully.
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
