Assuming your group of friends includes a person who loves coffee, perhaps you’ve heard the term, “coffee blooming.” It’s a lovely phrase, really, and once you understand what it is, you’ll see that its physical action is as beautiful as its name. It will also help you brew better cups of coffee, as coffee bloom is a vital part of the brewing process. Almost a reverse crema, the bloom is what gives coffee life.
If you thirst for coffee knowledge is as strong as ours, then let’s go learn about coffee bloom!
The bloom of coffee is when all of the gases that have been trapped inside the coffee bean start leaking out. This process begins when hot water is introduced to the grind. Then the bean absorbs and expands and at the same time, pushes out all the CO2 trapped inside. Where does the CO2 come from? It happens during the roasting process. Dark roasts, for example, have more of a bloom, as they are roasted for longer and more CO2 gets trapped inside.
This is how we can tell how fresh a bean is or how freshly roasted it is. The reason it matters is that there is a bunch of flavor in those gases, as well as aromatics. The less gas in your coffee, the staler it will taste. This makes sense because if a coffee doesn’t bloom, it’s probably old. Of course, coffee can go stale in many ways, and there are multiple factors to consider when discussing coffee bloom.
Coffee goes stale for the same reason that coffee blooms, it just takes longer. The moment coffee beans are pulled out of a roaster, they start losing the gas built up inside them. Therefore, you can tell how fresh your coffee is by how intense the bloom is. With certain extraction methods, you actually want to wait for the coffee to lose some of its gaseous nature, as an excessive amount can lead to a drink tasting ripe.
You will also probably not get much or any bloom out of pre-ground coffee. The gas inside a coffee bean normally sticks around for 10 days to two weeks, but once the coffee is ground, it begins rapidly escaping. This is also why the coffee world strongly urges people to invest in a grinder and buy their coffee whole bean.
The brewing method that showcases a bloom most easily is a Chemex. It is the first thing that happens when you swirl the hot water over the grinds. This process is even more neat to watch when you have a better understanding of what is going on. As the coffee expands, you can see the flavor going into the pot and smell it while it’s happening.
All sorts of things affect the bloom of a coffee. Many do so while it’s just sitting around. So, what are the variables?
Add coffee bloom to the list of things you now know about coffee! You can use it as a centerpiece for conversation, or maybe you will wind up being the friend who loves coffee! Either way, this is a powerful piece of information to have. You can talk to your friends through a brewing process and be able to spot stale coffee the moment water touches it. Happy brewing!
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