The bloom is the chaotic mixing of grounds, gases, and hot water. This phenomenon occurs when hot water is poured over ground coffee: The carbon dioxide (CO₂) that became trapped inside the coffee beans during the roasting process is now able to leave the bean thanks to the reaction created by entering in contact with the hot water.
It is important to have your coffee bloom to some extent because it facilitates the further flow of water through ground coffee.
Beans that have been roasted very recently will create a bigger bloom because not enough time has been allowed for the beans to de-gas. Conversely, beans that go long periods of the time incorrectly stored will create little or no bloom. If you purchase local coffee or roast coffee yourself, it is important to note that recently roasted beans will achieve the perfect bloom (not too little, not too much) about four to six days after roasted. Looking for more tips for storing your coffee beans? Check out “The Best Way to Store Your Coffee Beans” for more.
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How To Bloom Correctly Using the Hario V60:
- Place the filter in the Hario and rinse with hot water. This is to remove the taste of paper that you can sometimes get when using these filters.
- Pour 13 grams of ground coffee. If you’re using a scale, tare it now.
- Start your timer and pour water until all of the coffee is moistened. Let it sit for 30 seconds. Your coffee is beginning to bloom now: You can see bubbles making their way to the surface of the coffee.
- After the 30 seconds, start pouring again in a circular motion while you avoid touching the filter with the water. Coffee will now begin to really bloom: A sort of foam, usually light brown in color, will appear.
- Pour in intervals of 10 seconds until ready. If using a scale, the final extraction weight should be 200 grams.
The way that you pour your water is usually down to the person: I’ve seen people who make a dent in the center of the coffee before pouring water or people who don’t pause but instead pour water very slowly to maintain an even temperature of the coffee grounds. With experience, you’ll know which method you prefer.
Process Advice
In the past, people did not view the bloom in the same way as we do today. Although blooming coffee was used for coffee tasting events and was seen as a step of the coffee-making process, it was called “turbulence”, and too much of it was seen as undesirable.
Today, the bloom is sort of a spectacle, and Baristas search for ways to make the bloom last longer and look more pleasing to the customers when making the coffee: In some coffee shops, the coffee is bloomed (and brewed) in front of the customers for them to appreciate this part of the process.
For more helpful tips for your coffee shop, check out “8 Things You Should Know Before Opening a Coffee Shop” or “6 Coffee Shop Branding Tips“.
How To Bloom Coffee In a French Press:
- Prepare yourself as usual.
- When you pour water, don’t close the lid right away. Let it sit for thirty seconds.
- Now pour again water slowly as needed.
Bloom is seen anyway when making coffee in a French Press, but it tastes much better if we let it bloom properly. However, if the amount of bloom we are getting is excessive and we wish to reduce it, there are two things we can do about this:
Use a coarser grind. This will reduce the amount of coffee that is directly touched by hot water and so reduce the amount of gas that is released. Keep in mind that if you normally use a finer grind it will change in flavor.
Grind your coffee a few hours before brewing. The release of carbon dioxide is accelerated greatly when coffee is grounded, which is why it is always recommended, when one wants to achieve a good bloom, to use freshly grounded coffee. When you let ground coffee sit a few hours before, most of the gas released during the bloom will be gone already by the time you pour water over the coffee. This sounds counter-intuitive but it works if you don’t find too much bloom desirable and it does not impact taste as much as some would think. Take a look at this great coffee grinder to get those coffee beans to the right texture.
How To Bloom Coffee When Using Single-Serve Filters:
- Place the single-serve filter on the coffee cup.
- Pour ground coffee. For pour-over coffee I use a medium grind; you can use finer if you want a better-looking bloom.
- Pour water at 92 degrees Celsius until all the grounds are wet, then let sit for 15-20 seconds. Now pour the rest of the water slowly in a circular or spiral motion.
The Hard Bloom
An experiment was proposed: Would there be any difference at all if I were to bloom coffee with hard water rather than soft water?
Before we go any further, a clarification is needed. What is hard water?
Hardness in water is defined by the amount of calcium and magnesium. Usually, to avoid even the slightest effect on the taste of our coffee, soft water is recommended. Water filters convert hard water into soft water by replacing water’s calcium with sodium. Hard water is usually avoided like the plague, but…when the experiment was carried out, it turned out that using hard water to bloom coffee results in a much bigger bloom. Since the bloom is associated with coffee releasing gas that messes with flavor and aroma, this is all very confusing.
Thank you for reading with us today! Now that you know a bit more about how to make bloom coffee, let us know in the comments below if you have already tried to experiment on this. Still need a bit more insight into what coffee bloom is? Check out “What is Coffee Bloom?” for more info.
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We’ll brew ya later!! ☕️
