The Difference Between Pour-Over Coffee Bloom Times! How Much Water Should You Use for Drip Coffee Blooming? Blooming Tips for Coffee Brewing! How Long Should You Bloom Pour-Over Coffee?

The Importance of Bloom in Pour-Over Coffee

As the saying goes: "A good bloom makes for trouble-free brewing." For pour-over coffee preparation, blooming is an extremely important preparatory step.

The so-called bloom refers to the step where we pre-wet the coffee grounds with a small amount of hot water and wait for a certain period of time before formally extracting the flavor compounds from the coffee. Through this process, the carbon dioxide in the coffee that affects extraction is released during this stage, allowing the hot water we subsequently pour to better extract the flavor compounds from the coffee, making the coffee taste fuller.

However, mastering this blooming step requires considerable technique. Because the amount of water used during blooming is relatively small (typically twice the amount of coffee grounds), without certain pouring skills or experience, this hot water will struggle to wet all the coffee grounds, leading to some grounds being unable to release gas during the blooming stage, resulting in less rich coffee flavor.

If we want to avoid this situation, besides increasing the amount of water poured, we can also choose a more scientific approach to pouring! As FrontStreet Coffee often shares, scientific pouring allows hot water to more comprehensively saturate the coffee grounds, enabling more grounds to fully release gas during the blooming stage, thereby achieving a "perfect bloom." So the question arises: how exactly should we do it?

How to Achieve Perfect Bloom?

Generally speaking, uneven blooming mainly occurs with cone-shaped drippers. FrontStreet Coffee has shared in previous articles that because cone-shaped drippers have an inverted triangle structure, the same amount of coffee grounds will form a thicker coffee bed in a cone dripper compared to other shapes of drippers. Therefore, the path for hot water to flow downward is longer, making it easier for the water to find channels and deviate from the target path during percolation, failing to saturate the coffee grounds at the bottom.

Therefore, if we want to use a small amount of hot water to saturate the coffee grounds in the dripper as much as possible, we might try the following two pouring methods:

1. Concentrate Hot Water Injection in the Center

The first method is one that FrontStreet Coffee commonly uses - concentrating hot water injection in the center! Because the center of the coffee bed in a cone dripper is thickest, by concentrating hot water injection in the center, we can allow the hot water to permeate primarily from the center, reducing the occurrence of bypass water that prevents some coffee grounds from releasing gas, thus making gas release more uniform. The specific method is quite simple - for example, FrontStreet Coffee's most common approach is to pour in circles from the center outward. However, when circling in the center, the停留时间 will be longer and more water will be used. The specific method is shown in the following image:

Of course! We can also do it in reverse - pouring in circles from outside to center. Similarly, when circling in the center, the停留时间 can be longer. However, this pouring method has a drawback - it's not very suitable for fresher coffee beans with very high carbon dioxide content. This is because it will affect the gas release effect of the center coffee grounds, making it somewhat difficult for the center-positioned grounds to release gas.

2. Reduce the Thickness of the Center Coffee Bed

Another method is one that FrontStreet Coffee shared recently - digging a small hole in the center of the coffee bed, then concentrating hot water injection into the hole before pouring in circles outward. As shown in the following image:

Through this method, we can reduce the thickness of the coffee bed, allowing hot water to more easily contact the coffee grounds at the bottom and complete saturation. FrontStreet Coffee recommends that beginners adopt this method because it has lower requirements for water control during pouring compared to the previous method. Even novices who are just starting can easily achieve a perfect bloom.

Bloom Time Adjustment

In addition to pouring methods, we should also pay attention to bloom time. "Twice the amount of water as coffee, wait for 30 seconds" is a very classic blooming formula. For beginners, using the parameters in this formula is undoubtedly the most conservative method when starting out.

However, we all know that the gas content in coffee that hinders extraction varies due to freshness and roast level. Sometimes this time alone may not be sufficient to fully release these gases, and extraction efficiency will be reduced. In such cases, we can appropriately adjust the extraction time.

How to adjust? As FrontStreet Coffee often mentions, we need to first observe the state of the coffee bed during blooming. If the coffee bed still looks very "moist" after 30 seconds of blooming and continues to grow in size, this indicates that this bean has relatively high freshness and rich carbon dioxide content. For example, the following image shows what FrontStreet Coffee's Gold Mandheling, freshly roasted just a few days ago from their bean menu, looks like after 30 seconds of blooming. As you can see, it's not only very moist but also has continuous bubbles emerging.

This is because carbon dioxide forms bubbles when it emerges from the beans, and the presence of these bubbles reduces the speed of hot water penetration. Therefore, when carbon dioxide content is rich, the hot water will have slower penetration speed due to the continuously emerging gas. Even after the set 30 seconds, the state of the coffee bed looks no different from when we first poured the water. Furthermore, this coffee bed will gradually expand due to the continuous release of carbon dioxide. In such cases, we can appropriately extend the bloom time by 5-10 seconds, allowing the coffee grounds to release more carbon dioxide before proceeding with extraction, resulting in fuller coffee flavor.

On the other hand, if after pouring the bloom water the coffee bed dries up quickly and the swollen bag deflates rapidly (as shown in the following image), this indicates that there isn't much carbon dioxide left in the coffee grounds.

In this situation, we can appropriately shorten the bloom time, ending the bloom 5-10 seconds earlier to proceed with extraction. After all, without the carbon dioxide that hinders extraction, there's no need for blooming. However, if you're not very experienced and not yet good at judging, FrontStreet Coffee still recommends blooming for 30 seconds before starting extraction for the most stable approach.

Conclusion

So above are the two things we need to pay attention to during blooming: bloom time and pouring method. As long as we can evenly saturate the coffee grounds with hot water while giving the coffee grounds sufficient time to release gas, we can minimize the obstacles to extraction (carbon dioxide), better extract the flavor compounds from the coffee, and achieve fuller flavor.

Important Notice :

前街咖啡 FrontStreet Coffee has moved to new addredd:

FrontStreet Coffee Address: 315,Donghua East Road,GuangZhou

Tel:020 38364473