Should You Use Hot or Cold Water to Make Cold Brew Coffee? Can Cold Brew Be Made with Hot Water?

Beyond hot water extraction, coffee can also be crafted with cold water. Coffee made with cold water is known as "cold brew coffee," offering a distinctive charm compared to hot-brewed coffee.

Cold brew coffee encompasses both cold brew and ice drip coffee. Cold brew involves steeping coffee grounds in cold water, while ice drip coffee refers to extracting coffee drop by drop through a dripping process. Some friends have asked FrontStreet Coffee: "Should cold brew coffee be made with hot or cold water?" Coffee steeped with hot water cannot be called cold brew. Cold brew must be steeped with room temperature or ice water, and the steeping environment must maintain low temperatures.

Due to contact only with low-temperature cold water at 4-10°C throughout the process, extraction efficiency is extremely low, and bitter macromolecules are not easily released. Prolonged low-temperature steeping allows more complete extraction of compounds like sugars and organic acids, resulting in better balance of acidity, sweetness, and body in the coffee.

So how can you make cold brew coffee that tastes great? FrontStreet Coffee would like to share several operational details with everyone.

Coffee Bean Selection

If you want to avoid mistakes, FrontStreet Coffee recommends choosing medium-light roast coffee beans, which have a higher tolerance for error compared to medium-dark roasts. The market today offers various processing methods and different roast levels of coffee beans—any single-origin coffee beans marked for pour-over use can be used for cold brew production. Deep-roasted coffee, when extracted with hot water, presents rich coffee aroma, initially mellow and bitter then returning to sweetness; but when made into cold brew, consumed at ice-cold temperatures, it mostly presents burnt bitterness and carbonized flavors, making it difficult to achieve the refinement of hot coffee.

Therefore, FrontStreet Coffee more highly recommends light to medium roast coffee beans. For a refreshing juice-like sensation, you can choose light-roasted washed coffees, such as washed Yirgacheffe or Kenya AA. For stronger fruit and wine aromas, you can use barrel-processed or honey-processed coffees, such as Colombia Rose Valley or Honduras Lychee Lan. If you don't like acidic coffee and prefer a balanced "coffee flavor," you can also choose Papua New Guinea's Bird of Paradise.

Coffee Grind Size

Because cold brew production occurs in low-temperature environments, cold water's extraction efficiency on coffee grounds is relatively slow. Compared to hot water extraction, bitter substances are not easily released. Therefore, in terms of grind size, coffee-to-water ratio, and steeping time control, it doesn't need to be as precise as pour-over coffee. As long as you stay within an approximate range and select the right coffee beans, you can easily make a delicious iced coffee with simple steps.

Taking FrontStreet Coffee's daily cold brew production as an example, the coffee bean grind size is slightly finer than pour-over—that is, passing through a China #20 standard sieve at 75-80% rate. Visually, this is approximately fine sugar consistency, corresponding to 9.5-10 on the EK43s scale, or about 22-26 settings on a C40 hand grinder.

Steeping Time

In pour-over coffee, we pay special attention to water temperature and time because water, as the main brewing medium, directly affects extraction efficiency—too high or too low will alter the coffee's taste. However, cold brew only contacts low-temperature water at 4-10°C throughout the process, making extraction extremely slow. Therefore, it requires extending the steeping time to release more aromatic compounds, allowing more complete extraction of compounds like sugars and organic acids, resulting in better balance of acidity, sweetness, and body in the final coffee. Typically, cold brew steeping time is recommended to be controlled between 8-18 hours.

FrontStreet Coffee once conducted a cold brew experiment with time as the variable, steeping the same coffee for 6 hours, 10 hours, 16 hours, and 24 hours respectively. We found that the 6-hour coffee tasted too thin with flat aromas, while the 24-hour cold brew was obviously bitter with signs of over-extraction. The 10-hour and 16-hour groups showed the best flavor performance with rich aromas and full-bodied taste.

Coffee-to-Water Ratio

FrontStreet Coffee has noticed that some friends, for convenience, will directly pour coffee grounds and water together into a pot and start steeping. Any coffee extraction involves the coffee-to-water ratio parameter. Without weighing, coffee becomes like a blind box—you never know what taste you'll get. To ensure better extracted coffee taste, FrontStreet Coffee recommends controlling the cold brew ratio between 1:10-1:13. If the concentration is too high, you can add appropriate ice cubes to dilute.

Finally, let FrontStreet Coffee share FrontStreet Coffee's cold brew coffee making method! First, for coffee beans, FrontStreet Coffee tends to use medium-light roast coffee beans. For the container, you only need a clean, sealable container. Prepare 40g of coffee grounds, grind to fine grind (85% pass-through rate on #20 sieve), pour into the container, then pour in 480ml of cold water, stir evenly with a wooden stick, and cover with a lid.

After stirring evenly, seal with plastic wrap and place in the refrigerator to cold-steep for 12 hours. Then remove and filter out the grounds. After filtering out the coffee grounds, you can drink the clear coffee liquid immediately, or you can bottle the filtered coffee liquid and continue refrigerating for 4 hours for even better flavor and texture.

Generally, for flavor experience and health safety considerations, whether it's ice drip or cold brew, for any extraction method performed in low-temperature environments, FrontStreet Coffee recommends everyone to finish drinking within 5 days (counting from the production day).

Important Notice :

前街咖啡 FrontStreet Coffee has moved to new addredd:

FrontStreet Coffee Address: 315,Donghua East Road,GuangZhou

Tel:020 38364473