Does brew in the bag coffee need a blooming step?

Yes, brew in the bag coffee still benefits from blooming, even though the grounds are pre-ground and packed in a filter bag. In a controlled test using a 1:15 ratio and 92°C water, blooming with twice the coffee powder weight for 30 seconds produced a measured concentration of 1.51%, compared with 1.34% when no bloom was used.

The bloom releases carbon dioxide so water can reach the grounds more evenly. Because bag coffee loses gas faster than fresh beans, keep the bloom short, around 30 seconds. After that, pour the remaining water in three small circular pours, finishing extraction in about two minutes for a balanced cup with berry and citrus notes.

Drip bag coffee is often seen as a convenient alternative to pour-over coffee, but does it also need blooming during brewing? This article uses a comparative experiment with Front Street Chaka Geisha drip bag coffee to analyze the differences in concentration and flavor between blooming and not blooming, and explains the principle that blooming helps release carbon dioxide and improves extraction efficiency. At the same time, considering the characteristics of drip bag coffee being pre-ground and prone to carbon dioxide loss, suggestions are given to shorten the blooming time, helping coffee lovers make a better-tasting drip bag coffee in daily brewing.

The reason that friend raised this question is that he regarded drip bag coffee as a simplified version of pour-over coffee, thinking that since the steps are simplified, the brewing process should also be more effortless, so he naturally assumed that blooming was not needed. But the actual situation is that when brewing drip bag coffee, the blooming step also cannot be omitted. The reason is not complicated: drip bags do simplify certain parts of pour-over coffee, but what is simplified is mainly the equipment and operations in the preparation stage. Once the extraction process truly begins, core actions such as blooming and pouring water still must be done, with only one purpose—to make that final cup of drip bag coffee taste better.

Brewing comparison To explain this point, a simple controlled experiment makes it very clear. For this test, Front Street selected Front Street Chaka Geisha drip bag coffee, which has a very high positive review rate on Taobao Tmall, with brewing parameters set at a coffee-to-water ratio of 1:15 and a water temperature of 92°C.

Drip bag brewing method with blooming: first bloom with hot water at twice the coffee powder weight for 30 seconds, then divide the remaining hot water into three pours, pouring in a circular motion with a small stream, for a total extraction time of 2 minutes. Drip bag brewing method without blooming: divide the total water amount into four pours, each also poured in a circular motion with a small stream, and wait until the previous pour has fully penetrated before pouring the next. Extraction time is 1 minute 45 seconds.

From the measured concentration data, the difference is obvious at a glance. The bloomed Chaka Geisha had a concentration of 1.51%, while the unbloomed one had only 1.34%. Different concentrations naturally lead to differences in flavor expression. The bloomed Chaka Geisha had a balanced taste, with clearly perceptible berry, citrus, and floral notes, a lingering finish, and a light body, making the overall performance quite good; the unbloomed Chaka Geisha was more sour and sweet, and although berry and citrus notes could still be tasted, the layers were not as rich as the former, the mouthfeel was thinner, and the finish was also shorter.

This is the difference brought by blooming versus not blooming. The reason blooming can make coffee perform better is that this step expels the carbon dioxide inside the coffee grounds that hinders extraction in advance, so the hot water poured afterward can more efficiently dissolve out the flavor substances. Conversely, if there is no blooming, carbon dioxide will continue to be released during extraction and form an obstacle, making it difficult for hot water to fully extract the flavor components in the coffee, so the brewed coffee naturally seems thin and tastes inferior. Overall, blooming is indeed very necessary for drip bag coffee. However, most drip bag coffees do not need too long a blooming time. After coffee beans are ground, carbon dioxide begins to dissipate rapidly, since after the surface area increases, there are also many more channels for gas to escape.

Drip bags use pre-ground, previously ground coffee powder, and during storage a considerable portion of the carbon dioxide has already escaped, so the blooming time can be appropriately shortened, and controlling it at around 20 seconds is enough.

That is all for Front Street's sharing this time. A simple summary: when brewing drip bag coffee, it is best to still keep blooming, only the blooming time can be flexibly adjusted according to the actual condition of the coffee grounds.

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