Drink Dictionary

If you’ve never heard of Coffee Blooming before, welcome to the club! 🙂

While I thoroughly enjoy a cup of coffee, I wouldn’t consider myself a coffee enthusiast who try new techniques every week to try and find the best way to make my morning cup of coffee.

While I fully applaud those people, I just don’t have the equipment or time in the mornings to do so!

While I’ve developed a preference for what I like to drink, I’ll also pretty much drink anything with caffeine in it (desperate times call for desperate measures amirite)

I initially learned about coffee blooming a few months back, and while I have been practicing the process as part of my morning coffee routine, it’s always good to know why you’re doing something.

So if you’re new to the coffee blooming world like me, stay tuned to learn what the blooming process is, why its done, and a few other related items along the way!

Coffee Blooming:  Coffee blooming is a process in which you take a small amount of hot water and pour it over the coffee grounds that you are planning on using for your coffee.

The initial introduction of water to the grounds before brewing helps gas release from the grounds.

This gas would otherwise cause an uneven extraction of the coffee. The amount of gas released can depend on several things including roast level and the age of the beans.

The blooming process is thought to bring a richer and fuller flavor to the cup of coffee due to creating a more even extraction process by degassing the grounds before brewing.

While this method is most commonly done for pour-over coffee, you can bloom your coffee grounds for any method, including espresso!

Coffee Bloom: When the term coffee bloom is used, it refers to the state of the coffee grounds post-blooming. Typically, they are a bit fluffy or puffed up looking, as a lot of carbon dioxide (CO2) has just escaped the grounds.

To understand how coffee blooming works more in-depth, there are a few basic things you should know about the coffee roasting process.

Quick Coffee Roasting Basics

1. Roasted coffee beans get their color, aroma, and taste from a reaction that occurs during the roasting process called the Mailliard reaction.

2. This reaction, which occurs during roasting for all beans happens between the carbohydrates and sugars in the green beans and produces CO2 and other gases as a byproduct. 

3. Some of these trapped gases escape during the roasting process (hence the cracks on coffee beans), but CO2 especially, stays in the coffee beans and will slowly release from the beans as they age in a process called degassing.

4. The presence of CO2 in ground coffee prevents hot water from fully infiltrating the coffee grounds, potentially leading to under-extracted and more acidic-tasting coffee.

Many people prefer to not have an under-extracted cup of coffee, and this is where blooming your coffee grounds before comes in!

As I just mentioned, the issue with having CO2 gas remain in your coffee grounds (this is unavoidable btw) is that the water cannot fully get into the coffee grounds to extract the maximum amount of flavor. The gas basically blocks the water’s path into the coffee ground.

To deal with this, you pour a small amount of hot water onto the grounds before brewing. The grounds should be fully soaked and covered in water, but not drowned!

When you do this, you allow the remaining CO2 in the grounds to escape, as the water pushes it out of the way, creating space for the water to move into the coffee grounds for a beautifully extracted cup of coffee.

When this gas escapes, you might be able to see the grounds bloom visibly. The grounds may look puffier, or even fluffy after the bloom is done. After this point, you can continue to add the rest of the water to your pour-over as normal and wait until your cup of coffee is complete.

Here is a before and after shot of when I bloomed my coffee today.

While these photos may not be able to fully capture the texture changes of the coffee grounds, if you look along the edges of the grounds in the after photo, you may be able to spot where some of the gas bubbles have popped.

Here are a few extra things to keep in mind when it comes to the relationship between CO2 and coffee beans

1. Right after roasting, CO2 levels in the beans are the highest. 

Although it may seem like a good idea to brew with super fresh beans, it’s better to give the beans about a week after the roast date so they can degas properly before you use them.

If you buy your coffee beans in pre-packaged bags, you might notice a one-way valve on the front of the bag.

This allows the gasses being released to escape the bag without exposing the beans to more oxygen and air.

2. Carbon dioxide gas leaves ground beans quicker than whole beans.

You may have heard before that you want to grind your coffee right before you want to brew it.

This is due to the surface area being drastically increased when the coffee is ground, giving the CO2 way more chances to escape and leave your coffee stale if it sits for too long.

3. You can use the CO2 levels as a way of telling if your coffee is stale or getting a bit old.

Now, I’m not recommending you go buy sensors to measure your coffee bean’s CO2 levels.

However, if you decide to give coffee blooming a try and notice that no bubbles are coming out of your coffee grounds at all, your coffee may be getting a bit old.

4. The amount of CO2 that the bean contains can change based on the type of roast!

Since CO2 and the roasting process go hand in hand, it’s no surprise that there are different levels of gas in a light, medium, and dark roast.

As dark roasts are roasted for a longer time, there is more time for the gas to escape, leading to a less gassy roast.

I covered this a bit in the last section (oops) but we will cover it a bit more in-depth here!

The cut-and-dry, love it and leave it, way to bloom your coffee grounds is as follows:

Step 1: Set up your pour-over as you normally would i.e. filter set up, coffee grounds in, and ready to rumble

Step 2: Take the hot water you intend to brew with and pour a small amount in a circular motion over the coffee grounds until they are adequately saturated. Feel free to give it a swirl as well to make sure the water has gotten to every ground.

Note: You should be using the same water to bloom as you will brew with. A hot water temperature is crucial for blooming. 

While I eyeball the amount of water I use, it is recommended that you use twice the weight in water as the weight in coffee grounds (a solid 2:1 ratio)

Timewise you should wait around 30 seconds (or more if you please) to let the bloom fully occur.

Ideally, you should see some (or a lot) of bubbles come up to the surface here. These are the gasses escaping! You may also see the grounds puff or foam up.

Congratulations, you just bloomed your coffee grounds!! 🙂

If you don’t see any bubbles during this period, don’t fret! The beans may have already fully degassed before you used them or the coffee you are using is a bit on the older side.

Step 3: Begin your brewing process as you normally would. Hopefully, the bloom you just created has released the majority of the gasses in the grounds and now your coffee will properly extract!

While this method is most commonly used for pour-over coffee, it definitely can be used for other methods as well. I was shocked to find out you can bloom espresso but indeed you can! The steps will just be a bit different.

Blooming for French Press

If you’re a fan of the French press and want to give this a try, it’s pretty simple as well! Once your grounds are in the brew chamber, add enough hot water to fully saturate the grounds.

Give the mixture a good stir and then leave it to sit for around 20-30 seconds. This creates your bloom and then you can proceed as normal!

Blooming for Espresso 

Surprisingly, you actually can bloom the coffee grounds you’re using for espresso as well. This is formally known as “pre-infusion”.

While some machines may have the option to do it for you, if you want to try it manually it is a bit more tedious than the other methods.

You want to measure out around 10mL of hot water beforehand.

Once your grounds have been placed and tamped into the portafilter (see image below), you want to slowly and evenly pour the water onto the grounds, making sure every part of the puck is covered.

After this is done, attach the portafilter to the espresso head you want to use. After about 7 seconds, start pulling your espresso shot like normal!

Blooming for Drip Coffee/Classic Coffee Makers

If you’re rolling with your Mr. Coffee, no worries!

To bloom your grounds in preparation for drip coffee, simply add enough hot water to the basket where your grounds are, so the coffee is again, fully saturated, and let it sit for just over a minute or 60-90 seconds.

Different brewing methods require you to grind your coffee to different sizes.

A good example of this is espresso vs French press.

Espresso beans need to be ground very finely to allow the espresso shot to pull correctly. On the other hand, if you were to use a finer grind for the French press, you would end up with loads of grounds in your cup of coffee.

While I don’t believe the grind size matters when it comes to the blooming process, you will experience different flavor profiles with different grind sizes.

The finer the coffee is ground, you’re likely to have a coffee that is stronger and more intense due to the water interacting with more surface area.

If you’re using a coarse grind like for French Press, the extraction process will take a bit longer and you’ll end up with a less intense but still balanced cup of coffee.

Does blooming your coffee grounds before brewing actually change the way the coffee tastes? While the answer technically is yes, I truly think it depends on who you talk to.

In theory, when you allow time for the CO2 and other gasses to escape during the bloom, you’re setting up your grounds to be more evenly extracted, instead of under-extracted.

While under-extracted coffee may be more acidic, sour, and lack a “full mouth feeling”, a perfectly extracted cup of coffee should balance bitterness and acidity while having a full but not heavy body.

With that being said, I think this is one of those cases where if you are a proper coffee connoisseur, yes, you will probably be able to notice the difference in the flavor and texture of your coffee when it is brewed with or without a bloom.

If you don’t focus deeply on the flavor profiles of the coffee you drink typically, I’m not sure if you will notice a massive difference.

With that in mind, there is still no harm in blooming your coffee. I would not consider myself to be a coffee extraordinaire, but I still bloom my morning coffee out of habit.  Plus, it makes me feel kind of fancy, which is never bad.

You don’t have to be a coffee expert to step up you’re at-home coffee-making game!

Coffee blooming is a process that many people do before brewing their favorite cup of coffee. The purpose of blooming is to release all of the carbon dioxide and other gasses that exist in the coffee grounds so that hot water can adequately extract the coffee’s flavor during brewing.

During the roasting process, carbon dioxide and other gasses are created through an important reaction called the Mailliard reaction. This reaction is crucial in coffee roasting as it creates the beautiful coffee taste, color, and aroma that we all love.

The production of gasses are a result of the Mailliard reaction and thus are very important when it comes to roasting coffee. These gasses may leave the beans over time through a process called degassing, but typically some remain.

If there are too many gasses left in the grounds before brewing, the water isn’t able to fully infiltrate the grounds, leading to an under-extracted cup of coffee.

Under-extracted coffee tends to taste a bit thinner than your normal cup, and you may have a sour taste in your mouth after drinking.

The good thing about blooming coffee grounds? It’s extremely easy, straightforward to do, and can be done with practically any brewing method.

For using any type of pour-over method, all you need to do is prepare the pour-over coffee like you normally would.

It is best to use fresh coffee grounds rather than pre-ground but no worries if that is all you have!

Once your grounds are in place, you can eyeball the amount of water you want to add (this is what I do) or you can use twice as much water (in grams) as you used coffee. Regardless, the grounds should be fully saturated and submerged, but there should not be enough water where the brewing process will start.

Once you have saturated all of the grounds, feel free to give it a swirl, and then let the grounds sit for around a half minute or so.

If the grounds start blooming, you’ll most likely see some bubbles rise to the surface and the grounds might even look fluffy! After this point feel free to add the remaining water you’ve heated up and continue to brew your coffee like normal.

As I mentioned before, blooming your grounds is a simple way to try and elevate your at-home coffee making.

While I do believe mostly avid coffee drinkers who focus on the taste of the coffee will notice a major difference between a bloomed and non-bloomed cup of coffee, it can never hurt to try and create that more extracted cup of jo!

So there you have it. Blooming can be something you try out the next time you’re craving a cup of coffee. Take some time to enjoy it and see if you can notice the difference!

If you’re a fan of Blooming or have given it a go before and noticed a difference, drop a comment below, I’d love to hear about your experience!