What is Blooming in specialty coffee?
Blooming in coffee refers to the initial stage of brewing where freshly roasted specialty coffee grounds are briefly exposed to water, allowing the release of trapped carbon dioxide (CO2) and other gases. This process is necessary for several reasons:
- Freshness Indication: The bloom indicates the freshness of the specialty coffee. If the coffee is fresh, it will release a significant amount of CO2, causing the grounds to bubble and foam. If the coffee is stale, the bloom will be minimal or nonexistent.
- Flavor Enhancement: Allowing the specialty coffee to bloom helps to release the trapped CO2, which can otherwise infuse a sour taste into the coffee. By releasing the CO2, the water can then extract the flavors and oils from the coffee more effectively, resulting in a better-tasting brew.
- Even Extraction: The bloom helps to ensure even extraction of flavors by allowing the water to penetrate the coffee grounds more evenly. This is particularly important in pour-over and other manual brewing methods suited for specialty coffee where the water flow can be controlled.
- Prevents Turbulence: The bloom prevents turbulence during brewing, which can occur when the CO2 is released rapidly, pushing the water away from the grounds and leading to under-extraction. By releasing the CO2 initially, the water can then interact with the specialty coffee grounds more smoothly.
To bloom specialty coffee, a small amount of water (usually twice the weight of the coffee) is poured over the grounds, and the mixture is allowed to sit for 30 seconds to a minute before adding the rest of the water. This process helps to ensure a well-balanced and flavorful cup of coffee.
Why is Blooming important in specialty coffee preparation?
The idea behind blooming is that by releasing CO2, you can achieve a less bitter drink. This is because when CO2 comes into contact with water, it forms a weak acid called carbonic acid (H2CO3), which decreases the pH of the coffee. The ions generated in this reaction are then diluted in water, causing it to become saturated more quickly. Ultimately, this results in less extraction of the specialty coffee, leading to a smoother flavor.
Does Blooming really make a difference in taste?
The most crucial question in coffee brewing is whether blooming truly makes a difference. Many people follow the practice without ever questioning its impact. To answer this, we conducted blind experiments, brewing the same specialty coffee with the same recipe, both with and without blooming. The results were:
- Bloomed Coffee: Richer, more flavorful, and rounder.
- Un-bloomed Coffee: Flatter, hollow flavor, and more acidic.
However, when we blind-tested these coffees with people who don’t regularly drink specialty coffee, they couldn’t discern much of a difference. The conclusion is that there is a difference, and since blooming is a simple step, it’s worth taking the extra effort.
