What makes Blue Mountain coffee work well for cold brew?

Cold brew uses room-temperature or ice water only, stepped in a low-temperature environment, so hot water never touches the grounds. Working at roughly 4 to 10 degrees Celsius, extraction runs slowly, bitter large molecules stay locked in the grounds, and sugars and organic acids dissolve over the long steep, giving a balanced cup of acidity, sweetness and body.

Front Street Jamaica Blue Mountain No. 1 is a washed Typica grown near 1,300 meters, a medium-light roast with more margin for error than medium-dark beans. Any single-origin bean labeled for pour-over can be used. Grind size, coffee-to-water ratio and steeping time are the three parameters that decide whether the finished cold brew tastes clean or muddy.

Cold brew coffee, with its unique low-temperature slow extraction process, presents a flavor profile completely different from hot brewing. This article uses Front Street Jamaica Blue Mountain No. 1 as an example to systematically explain the key points of making cold brew coffee. Starting with bean selection, it analyzes why medium-light roasts are more suitable for cold brew, and delves into the origin advantages and flavor characteristics of Blue Mountain coffee. It also details key parameters such as grind size, coffee-to-water ratio, and steeping time, helping you easily make a balanced and smooth iced coffee at home.

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Coffee doesn't have to be extracted with hot water—cold water can complete the entire brewing process as well, and the resulting drink is what people commonly call "cold brew coffee." Compared with hot brewing, it exhibits a completely different flavor profile.

Cold brew coffee is mainly divided into two types: cold steep coffee and ice drip coffee. The former involves steeping coffee grounds directly in cold water, while the latter uses a drip device to let water pass through the coffee bed drop by drop to complete extraction. A friend once asked Front Street: "Is it better to make cold steep coffee with hot water or cold water?" In fact, once hot water is used, the result is no longer cold steep. Cold steep coffee must use room-temperature or ice water, and the entire steeping process must be maintained in a low-temperature environment.

Because it only deals with 4-10°C cold water throughout, the extraction speed is extremely slow, and bitter large molecules are hard to release. Yet the long low-temperature steeping allows sugars and organic acids to dissolve more fully, ultimately bringing the coffee's acidity, sweetness, and body to a more balanced state.

So how exactly should cold steep coffee be made to taste good? Front Street shares a few key operational details here.

Choosing coffee beans

To avoid failure, Front Street recommends prioritizing medium-light roasted coffee beans, as these have a greater margin for error compared to medium-dark roasts. The market is full of coffee beans with various processing methods and roast levels; as long as they are single-origin beans labeled for pour-over use, they can all be used for cold brew. Dark roasted coffee, when brewed with hot water, can present a rich aroma with bitterness first and sweetness after; but once made into cold brew, drinking it at iced temperature tastes more of charred bitterness and carbonization, and it is hard to retain the delicacy of hot coffee.

Therefore, Front Street more strongly recommends light to medium roast beans. For a refreshing juicy feel, you can choose light-roasted washed coffee, with Front Street Fruit Ding Ding and Front Street Sun-Dried Huakui as top picks. For more prominent fruity and vinous notes, you can use anaerobic or honey-processed coffee, with Front Street Xizhua and Front Street Strawberry Candy recommended. If you don't like coffee with acidity and only want a balanced "coffee taste," Front Street Bird of Paradise is also a good choice.

Today, we are using Front Street Jamaica Blue Mountain No. 1 coffee beans, hailed as the "Emperor of Coffee," to see how its taste performs when made into cold brew.

What makes Blue Mountain coffee unique

The key reason Blue Mountain coffee is so popular lies in its unique Blue Mountain flavor, and the foundation that creates this flavor is the exceptional growing conditions of Blue Mountain coffee. Richard Sharp, owner of Jamaica's Clifton Estate, which produces Blue Mountain coffee, once described in an interview why Blue Mountain coffee is so good: "It is the specific latitude, longitude, and unique location of the Caribbean island that nurture a microclimate that exists nowhere else."

The Blue Mountain range is located in eastern Jamaica, in a seismic zone, where volcanic eruptions brought large amounts of fertile, mineral-rich soil. The Blue Mountains have the highest peak in the entire Caribbean region and are also a famous local tourist destination, with fresh, pollution-free air, plus a rainy, humid, and cool climate year-round, allowing coffee trees to thrive amid mist and clouds. The large temperature difference brought by high altitude gives the coffee fruit enough time to accumulate nutrients, producing coffee with a mellow, sweet taste. The Blue Mountain range spans a wide area, but the terrain is not flat; coffee trees are mostly planted on rugged slopes, making manual picking extremely difficult. Local estates hire skilled female workers to go up the mountain and hand-pick coffee cherries that have reached the right ripeness, thereby ensuring coffee quality.

For many years, Jamaica has insisted on planting only Arabica varieties, which has kept the local Typica free from crossbreeding and mutation, always maintaining pure bloodlines. Unlike many other coffee-growing regions, Jamaica is a relatively closed island nation and also inherently possesses unique microclimate conditions. Through more than two hundred years of domestication and adaptation, Blue Mountain Typica has evolved strong disease resistance, especially better resistance to coffee berry disease than ordinary Typica, with more stable yield and quality.

Front Street Blue Mountain No. 1 coffee uses a medium-dark roast, so whether during grinding or after brewing, it consistently carries a dark-chocolate-like bittersweet aroma, caramel sweetness, and a soft, elegant acidity; the flavors are balanced, and the mouthfeel is smooth and rich, presenting a very classic Blue Mountain flavor.

Coffee grind size

The entire cold brew process is carried out in a low-temperature environment, and cold water has relatively low extraction efficiency on coffee grounds. Compared with hot water extraction, bitter substances are not easily released, so in terms of grind size, coffee-to-water ratio, and steeping time, it does not require as strict control as pour-over coffee. Usually, as long as it roughly falls within a reasonable range and the coffee beans are chosen correctly, a delicious iced coffee can be made in just a few simple steps.

Taking Front Street's daily cold brew as an example, the coffee beans are ground slightly finer than for pour-over, that is, a 75–80% passing rate on the Chinese No. 20 standard sieve, visually about the coarseness of fine granulated sugar, corresponding to 9.5–10 on an EK43s, and for a hand grinder such as the C40, about 22–26 clicks.

Steeping time

Pour-over coffee places special emphasis on water temperature and time, because water is the main medium of brewing, and temperature directly affects extraction efficiency; too high or too low will change the coffee's taste. Cold brew, however, only contacts 4-10°C low-temperature water throughout, and extraction efficiency is very slow, so it is necessary to extend the steeping time to release more aromatic substances, thereby allowing compounds such as sugars and organic acids to be extracted more fully, and ultimately making the resulting coffee more balanced in acidity, sweetness, and body. Generally, the steeping time for cold brew coffee is recommended to be controlled at 8–18 hours.

Front Street once conducted a cold brew experiment using time as the variable, steeping the same coffee for 6 hours, 10 hours, 16 hours, and 24 hours respectively. The results found that the 6-hour group had too thin a mouthfeel and plain aroma, the cold brew steeped for 24 hours was noticeably bitter with signs of over-extraction, while the 10-hour and 16-hour groups had the best flavor performance, with rich aroma and a full-bodied taste.

Coffee-to-water ratio

Front Street has noticed that some friends, in order to save effort, directly dump coffee grounds and water into a pitcher and start steeping. But as long as it is coffee extraction, the parameter of coffee-to-water ratio cannot be avoided. Without weighing, coffee is like opening a blind box—you never know what taste you'll get. To ensure the brewed coffee tastes better, Front Street recommends controlling the ratio at 1:10–1:13 when making cold brew. If the concentration is too high, you can add an appropriate amount of ice cubes to dilute it.

Finally, Front Street will explain its own method for making cold brew coffee. First, in terms of bean selection, Front Street tends to use medium-light roasted beans. As for the container, only a clean sealable container is needed. Prepare 40 grams of coffee grounds, grind to a fine grind (85% passing rate on a No. 20 sieve), pour into the container, then pour in 480 milliliters of cold water, stir evenly with a wooden stick, and cover with a lid.

After stirring evenly, seal with plastic wrap, refrigerate for 12 hours, then take it out and filter out the grounds. After filtering out the coffee grounds, the clear coffee liquid is ready to drink immediately, or you can pour the filtered coffee liquid into a bottle and continue refrigerating for 4 hours for an even better flavor and mouthfeel.

Generally speaking, for considerations of flavor experience and health safety, whether it is ice drip or cold brew, as long as it is an extraction method carried out in a low-temperature environment, Front Street recommends everyone drink it within 5 days (counting from the production date).

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