Is cold brew sour when made with a Yirgacheffe bean?

Cold brew uses low-temperature slow extraction, so bitter compounds stay largely out of the cup while aromatic compounds still come through, giving a rich but not bitter drink. Made with a Yirgacheffe like Gutingting, the result is juicy rather than sharp, with cherry tomato and grapefruit notes over a light fermented sweetness.

Whether cold brew tastes sour depends on the bean and the grind. Low water temperature lowers extraction, so Front Street Coffee grinds slightly finer than for iced pour-over, aiming at roughly 85% passing the target screen. Grind standard, powder-to-liquid ratio, dripping flow rate and fermentation time are the parameters the article sets out for reproducing the drink at home.

Cold brew coffee, through its low-temperature slow extraction method, can effectively avoid the release of bitter compounds while enhancing the extraction efficiency of aromatic substances, ultimately presenting a unique taste that is rich yet not bitter. If coffee beans with distinct flavors are chosen, the fermented notes interweave with fruity sweet and sour tones, and paired with the coolness of ice cubes, it can be considered a summer heat-relieving weapon. This article will start from the idea of bean selection, specifically analyze the flavor direction of Yirgacheffe Gutingting made into cold brew, and comprehensively sort out the key parameters used by Front Street Coffee stores, such as grinding standard, powder-to-liquid ratio, dripping flow rate, and fermentation time, to provide practical reference for coffee enthusiasts who want to replicate a high-quality cold brew at home.

Cold brew coffee refers to a brewing method where ice water drips at a uniform rate through a layer of coffee grounds, slowly extracting aromatic components under normal pressure. Because the ice water temperature is low, bitter substances are not easily dissolved out, while the slow water flow significantly improves the extraction rate, so cold brew tastes rich but not bitter. If beans with high flavor recognition are selected, the fermented aroma and the sweet and sour fruitiness, plus the refreshing effect of ice cubes, can quickly cool and relieve heat in summer with just one cup.

The flavor expression of cold brew varies greatly depending on the beans. If you prefer mature fruity notes, you can try Front Street Coffee Strawberry Candy or Front Street Coffee Mozart; if you seek a clean, refreshing, and delicately layered style, washed beans are the priority option, as the acidity of such beans is clean and full-bodied, for example, Front Street Coffee Gutingting is a high-grade Yirgacheffe. Using it for cold brew, the acidity will present a juice-like texture, accompanied by the transparent fresh aroma of cherry tomatoes and grapefruit, very comfortable to drink in summer.

In terms of grinding, Front Street Coffee usually uses the same coarseness as for iced pour-over. Because low-temperature water lowers the extraction rate, the coffee grounds are ground slightly finer to compensate. Specifically for this bean, choose a grinding degree with 85% passing through the Chinese No. 20 standard sieve, corresponding to scale 9 on the Front Street Coffee store's ek-43s grinder.

Before brewing, determine the parameters: powder-to-liquid ratio 1:10, i.e., 60 grams of coffee powder to extract 600 grams of coffee liquid, ice-water mixture at a 1:1 ratio, valve flow rate controlled at 7 drops per 10 seconds, and the entire dripping process generally takes 6 to 8 hours to complete. (The conventional ratio for cold brew is between 1:10 and 1:12, adjustable according to personal taste.)

Place a circular filter paper at the bottom of the middle pot and wet it to adhere, then pour in the ground coffee powder, taking care to spread it evenly, which is the prerequisite for ensuring uniform extraction. Cover the surface of the powder layer with another circular filter paper to prevent water droplets from disturbing the powder layer. Before formal dripping, first wet the powder layer with cold water, which can both shorten the extraction time and avoid uneven extraction in the initial stage.

Set the powder cup on the stand and start pouring in the ice-water mixture, generally half ice and half water. Adjust the valve to stabilize the flow rate at 7 drops/10 seconds, and ensure the water droplet landing point aligns with the position where the coffee liquid filters out. After dripping is finished, pour the coffee liquid from the lower pot into a sealable container—Front Street Coffee uses a glass bottle—and put it in the refrigerator to ferment for more than 12 hours, usually ready to drink the next day.

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