What is coffee blooming?

Coffee blooming is one of the lesser-known aspects of coffee brewing that can both confuse and excite coffee nerds around the world.  This confusion, in part, is due to the connotations the word “blooming” brings to anyone’s mind—it sounds like something your favorite flower does on a fresh spring morning, right? However, the excitement over the term coffee "blooming" has to do with how it can enhance the flavors in your favorite cup, and that's exactly what this blog post is all about. 

Don’t let the weird naming conventions fool you: coffee “blooming” is a highly scientific, widely overlooked, and extremely important aspect of the flavor extraction processes that occurs each time you brew up your favorite cup of coffee.  

For anyone that loves coffee, learning how to take advantage of blooming is important for yielding better coffee flavor. So... what exactly is “blooming” coffee, then? 

This week’s Alma-nac blog will walk you through a brief overview of coffee blooming, including what it actually is, why it’s important, and how you can learn to take advantage of it to yield better tasting cups of your favorite coffee! 

Before we answer that question in a direct way, we want to stress that coffee can be as scientific or as casual as you want it to be. Although what we are about to start describing what sounds like highly important information (and it definitely is), that doesn’t mean you can’t enjoy coffee your way with or without mastering the art of “blooming” your cup a’ joe.  

To first understand blooming, you need to first understand what happens when you brew coffee: In its roasted state, coffee beans are densely packed with locked carbon dioxide molecules that, during the brewing process, are activated and released by the high temperature of boiling water. This gaseous release of CO2 occurs every time you press “brew” on your at-home coffee machine no matter the brew, bean, or roasting profile, and will be more present with freshly roasted and ground coffees. 

Although we could probably spend an entire blog talking about the gaseous release of CO2 and the chemistry of coffee brewing (and we probably will because “chemistry of coffee” is a killer title), understanding the actual molecular-level science occurring during the brewing process is irrelevant to understanding why blooming is important.  

What you do need to understand, however, is that this initial release of CO2 during the brewing process can hurt or hinder your final brew’s flavor, and this is where a strategy called “blooming” comes in to the equation.  

If you’ve ever made a V60 or Chemex pour over, you may have noticed that your coffee grounds rapidly expand and start bubbling up when you first pour water into the carafe, which is the natural release of CO2 we talked about just a second ago. 

During the initial stages of this CO2 release, the full range of flavors within the coffee grounds are prevented from transferring into the water by the rapid expansion of carbon dioxide. Sometimes this process can take a few seconds, while other times it can take up to a minute; regardless, pour-over brewing methods such as the V-60 or Chemex have no way of capturing these flavors, especially if water is transferred through the grounds before the coffee has time to naturally “de-gas.”  

This is where a strategy called “blooming” can be implemented to circumvent the loss of flavor transfer caused by the gaseous release of carbon dioxide.  

IMPORTANT NOTE HERE: In immersion brewing devices like a French Press or AeroPress, the bubbling CO2 isn’t as effective in preventing coffee’s natural flavors from transferring to the water, but you definitely want to try to “bloom” your coffee to some degree in devices that don’t fully immerse the grinds during the brewing process.  

In order to prevent carbon dioxide from hindering the full flavor potential of your grounds at the beginning of brewing, blooming is the process of using small amounts of boiling water to “de-gas” CO2 from your coffee before pouring in the rest of the water.   

To do this, especially in a pour-over device, simply add about 10-20% of the total amount of water you need for brewing and wait roughly 30-60 seconds to allow oxygen’s arch-nemeses, CO2, to fully escape the delicious chemical reaction you are creating.  

While you wait, it’s also important to swirl/mix the grinds fully in the added water to make sure all of the grounds are submerged so that all of the CO2 is escaping; you can also savor the sweet aroma of this de-gassing process while you wait, although that is completely optional.  

Once you stop seeing new bubbles appear in your grinds, you’ll know it’s time to continue with your brewing process!  

Coffee blooming is optional and definitely not a requirement for brewing delicious coffee. But, if you are wanting to experience a coffee with a wide array of possible flavor notes, such as Alma’s Natural Process and Honey Process, blooming can be a game changer that takes your Sunday pour-overs to the next level!  

In our own brew guide videos, namely the V60, we always encourage people to bloom their coffee to taste, which means finding that ideal bloom duration that works for you and your favorite roast. This process might take you time to dial in, but if you love the taste of your favorite Alma Coffee roast a bit of R&D might be worth the few over or under extracted brews. 

Again, as we stressed at the beginning of this blog, coffee is about you at the end of the day. There is no “correct” way to enjoy your favorite coffee’s flavors, and if anyone tells you differently, please point them to a blog we just published on the Coffee Flavor Wheel to hush them up.  

If you’ve never heard of blooming before, it might be worth a try! We’d love to hear your thoughts on the importance (or non-importance) of coffee blooming below; or, if you experiment with blooming any of Alma Coffee’s roasts after reading this, drop a comment later and let us know if you tasted the difference.  

Until next week’s blog, cheers!