How does a long brew change the flavor of coffee?

Cold brew coffee is made by mixing coffee grounds with ice water and extracting slowly over a long period at low temperature. That long brew reduces acidity and astringency, pulls out small-molecule floral and fruity notes, and leaves heavier smoky notes behind. The result is a soft, sweet, bright cup that can keep in the refrigerator for about two weeks and sometimes shows a faint wine-like aroma from fermentation.

Hot brewing uses water at 82 to 95 degrees Celsius and finishes in under three minutes, so it extracts a wider range of compounds. Cold brew works differently: low temperature plus long contact time means mainly the lighter flavor compounds come through. Frontstreet Coffee notes that the method also suits delicate single-origin beans, so the terroir of a growing region stays readable in the cup.

Cold brew coffee has surged in popularity in recent years, offering a rich, smooth taste through its low-temperature slow extraction process, lower caffeine content, and a shelf life of up to two weeks—it may even develop a subtle wine-like aroma from fermentation. What makes it so special? How can you easily recreate the Starbucks flavor at home? And which coffee beans should you choose? Front Street Coffee will reveal it all for you, from the principles of cold brew and recommended bean varieties to specific brewing steps and flavor analysis, so you too can become a cold brew expert. We'll also share practical tips for pour-over beginners to avoid failure.

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Cold brew coffee, highly sought after in recent years, uses low-temperature slow extraction to make the coffee richer and sweeter, with relatively lower caffeine content, and it can typically be refrigerated for about two weeks. Through fermentation, it sometimes gives off a subtle wine aroma. So how do you make cold brew coffee, and how do you master the ratio? Front Street will now teach you how to make Starbucks-style cold brew coffee, along with foolproof tips for pour-over beginners! You too can become a coffee expert!

[Characteristics of Cold Brew Coffee]

Cold brew coffee is made by mixing coffee grounds with ice water in a specific ratio, then extracting slowly over a long period. This low-temperature process significantly reduces the coffee's acidity and astringency. Due to the low-temperature environment and prolonged contact between the coffee grounds and water, only small-molecule flavor compounds—such as floral and fruity notes—are extracted, while larger-molecule flavors like smoky notes are less likely to be released.

Low-temperature extraction and long extraction time are the two core characteristics of cold brew coffee, and they are what mainly distinguish it from hot-brewed coffee. Hot brewing uses water at 82–95°C, with a brewing time usually not exceeding 3 minutes. Cold brew coffee itself can fully showcase the delicate flavor layers of coffee, with soft acidity, sweet taste, bright mouthfeel, and mellow flavor, presenting the unique terroir characteristics of specialty coffee regions.

[Coffee Beans Suitable for Making Cold Brew at Home]

The prerequisite for a good cup of coffee is high-quality coffee beans, and the beans used for cold brew should naturally be of high quality as well. Front Street's roasting philosophy is "freshly roasted good coffee," hoping every customer can enjoy freshly roasted beans with full aroma. All shipped coffee beans are freshly roasted within 5 days. Below, using coffees from Front Street's bean list as examples, we introduce which coffee beans are suitable for making cold brew at home.

If you prefer sweet and fruity flavors, we recommend these three specialty coffee beans: Front Street Gutingding, Front Street Strawberry Candy, and Front Street Huakui. They are not only rich in fruity aroma but also showcase delicate sweet-and-sour notes under low-temperature extraction.

If you prefer a balanced taste, we recommend Front Street, Diamond Mountain, Front Street Kafa Forest, and Front Street Gesha Village Chaka—they offer a good balance of sweetness, acidity, bitterness, and mellowness. If you only love rich, dark-roasted coffee, then start with these single-origin coffees: Front Street Queen's Estate, Front Street Bird of Paradise, Front Street Golden Mandheling, and Front Street Huilan.

[Front Street Yirgacheffe Gutingding]

Yirgacheffe Gutingding

Country: Ethiopia

Region: Yirgacheffe Gedeo Zone

Altitude: 1900-2300m

Variety: Heirloom

Processing Method: Washed Grade: G1

[Starbucks Cold Brew Coffee Recipe]

Coffee Beans: Front Street Gutingding Cooperative

Dose: 20g

Water-to-Coffee Ratio: 1:12

Grind Size: Coarse grind (slightly coarser than regular pour-over grind to avoid over-extraction)

Steeping Time: 8–10 hours

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

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

③ Filter out the coffee liquid using a filter cloth or filter paper.

[Front Street Coffee Flavor Description]

Floral, citrus, berry. After continuing to refrigerate for 5 hours, the berry aroma becomes more prominent, with a refreshing citrus entry, light sweetness, and a clean mouthfeel.

[Pros and Cons of Cold Brew Coffee]

Pros: Front Street believes that the cold brew method amplifies the coffee's flavor and aroma while reducing acidity—the colder, the better it tastes. Without hot water brewing, the low-temperature ice water does not extract impurities or bitterness from the coffee beans, so the taste is clean and pure, fresh, slightly sweet, and smooth.

Cons: Front Street believes that due to the long contact time between water and coffee grounds, it has the highest caffeine content, making it ideal for moments when you 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 in cold water, which increases the coffee's acidity and bitterness. 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.