What is the process description of making coffee by cold brew?

Cold brew coffee is made by steeping ground coffee in cold or ice water for at least 12 hours, then filtering it. A coarser grind and a set ice-water-to-coffee ratio keep the extraction even. The low temperature and long contact time produce a clean, smooth, low-acid drink that suits summer brewing.

The method was first proposed by Toddy Simpson, a Cornell chemical engineering student, after he tried an old-style Peruvian iced coffee; Starbucks later popularized it for summer iced drinks. Cold water extracts fewer acids in coffee, which is why the result tastes rounder and less sharp than hot brewing. Extending the steep to 24 or 48 hours builds a fuller body.

In the heat of summer, a refreshing low-acid cold brew coffee has become a favorite for many coffee lovers. But to make a delicious cold brew at home, how coarse should the grind be? How should the ratio of ice water to coffee grounds be set? How long should it steep? This article starts with the origin, extraction principles, and flavor characteristics of cold brew, explains key parameters such as water-to-coffee ratio and grind size in detail, and includes Front Street Coffee's practical recipe and flavor description, helping you fully master the details of making cold brew coffee, avoid common pitfalls, and easily create a clean, smooth iced drink.

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Making cold brew coffee is not complicated; it is refreshing on the palate, low in acidity, and rich in flavor, making it an ideal drink for midsummer. Because of this, many people want to try it at home and have asked Front Street Coffee about extraction methods and details to note. So without further ado, let's talk about the various details of cold brew coffee, from making it to its flavor.

While researching, Front Street Coffee (FrontStreet Coffee) learned that the concept of cold brew coffee was first proposed by Toddy Simpson. He was a student majoring in chemical engineering at Cornell University in the United States. After once drinking an old-style Peruvian iced coffee, he invented a set of equipment for making cold brew coffee and named it Todd. Later, this technique was introduced by Starbucks to make summer iced drinks.

The English name for cold brew coffee is Cold Brew Coffee. The method is to put ground coffee beans into cold water to steep, usually for at least 12 hours, and then filter and extract it with professional equipment. If you want a fuller body, you can also extend the time to 24 to 48 hours. Broadly speaking, any method of extracting coffee at low temperature can be included in the category of cold brew. Low temperature and long extraction time are precisely the two major characteristics of cold brew coffee.

The Extraction Principle of Cold Brew Coffee

The method of making cold brew coffee is to mix coffee grounds with ice water in a specific ratio and then obtain coffee liquid through slow extraction. Because of the low-temperature environment and long contact with coffee grounds, in the end only small-molecule flavor substances are released, such as floral and fruity notes; flavor substances with larger molecular weights, such as smoky notes, are difficult to extract. Therefore, coffee made by the cold brew process has noticeably lower acidity and astringency.

What Are the Flavor Characteristics of Cold Brew Coffee?

Low-temperature extraction and long extraction time are the two major characteristics of cold brew coffee and also the main differences between it and high-temperature extracted coffee. High-temperature extraction uses hot water at 82 to 95°C to extract coffee beans, and the time usually does not exceed 3 minutes. Cold brew coffee itself can fully display the subtle flavor layers of coffee, with mild acidity, sweet taste, bright mouthfeel, and gentle flavor, and can present the terroir characteristics of specialty coffee origins.

The Water-to-Coffee Ratio for Cold Brew

Front Street Coffee (FrontStreet Coffee) believes that the suitable water-to-coffee ratio for cold brew is about 1:10 to 1:16, and it can be adjusted according to personal preference for strength. Front Street Coffee (FrontStreet Coffee) usually uses a 1:15 water-to-coffee ratio; at this ratio the taste is just right. If you prefer it stronger, you can also try 1:10.

The Grind Size for Cold Brew

The finer the coffee is ground, the more substances will be extracted in the same amount of time. However, if the grind is too fine, over-extraction is likely to occur during the extraction process. Considering that cold brew is a low-temperature, long-time extraction, Front Street Coffee (FrontStreet Coffee) recommends a coarser grind than for pour-over coffee beans.

[Front Street Coffee (FrontStreet Coffee) Yirgacheffe Gutingding]

Country: Ethiopia

Region: Yirgacheffe Gedeo Zone

Altitude: 1900-2300m

Variety: Heirloom

Processing Method: Washed Grade: G1

[Front Street Coffee (FrontStreet Coffee) Preparation Method]

Coffee dose: 20g

Water-to-coffee ratio: 1:12

Grind size: coarse grind (slightly coarser than normal pour-over grind to avoid over-extraction)

Steeping time: 8-10 hours

① First, grind the coffee and pour it into a jar, then add 240ml of water.

② Place it in the refrigerator to extract for 13 hours, allowing the coffee grounds to fully contact the cold water.

③ Filter out the coffee liquid with filter cloth or filter paper.

[Front Street Coffee (FrontStreet Coffee) Flavor Description]

Floral, citrus, berry. After continuing to leave it in the refrigerator for 5 hours, the berry aroma became more prominent, with a refreshing citrus entry, clean sweetness, and a clean mouthfeel.

[Advantages and Disadvantages of Cold Brew Coffee]

Advantages: Front Street Coffee (FrontStreet Coffee) finds that the cold brew method amplifies the coffee's flavor and aroma and lowers the acidity, and the colder it is, the better it tastes. Without hot water brewing, low-temperature ice water will not extract impurities and bitterness from the coffee beans, so the taste is clean and pure, fresh, slightly sweet, and smooth.

Disadvantages: Front Street Coffee (FrontStreet Coffee) finds that because the water and coffee grounds are in contact for a long time, it has the strongest caffeine content, making it very suitable for drinking at moments when you most need to stay highly alert. Roughly calculated, a cup of cold brew coffee (200ml/20g beans) contains about 200mg of caffeine;

Does cold brew coffee become sour? Yes. In hot brewing, the oils and acids in coffee beans degrade and oxidize faster than with cold water, which increases the acidity and bitterness of the coffee. The low temperature and long brewing time of the cold brew process capture more sweet compounds soluble in cold water, without the oils and acids.

The above content is compiled by CoffeeHunters, a coffee news website.