Should the Coffee Drip from Pour-Over Bloom Be Discarded? How Much Water is Needed for Coffee Bloom?

Introduction

Generally, the amount of water used for blooming is twice the weight of coffee grounds, as the saturated water absorption capacity of coffee grounds is twice their own weight. However, in practice, when adding twice the amount of water during the initial pouring stage, excess coffee liquid will drip into the lower pot. Should this coffee liquid that drips into the lower pot be discarded?

Why Does Excess Coffee Liquid Exist?

First, let's explain this issue. As we've mentioned before, the saturated water absorption capacity of coffee grounds is twice their own weight, but this is under saturation conditions. This means that in the initial stage, when water first contacts the coffee grounds, time is needed for penetration. When the coffee grounds are coarse, water may not fully penetrate before dripping into the lower pot due to gravity. The coarser the grounds, the larger the particle size, the longer the penetration time, and the larger the gaps between coffee particles, resulting in more coffee liquid dripping into the lower pot, and vice versa.

To Discard or to Keep?

It's quite simple - we can find the answer through a comparative experiment. First, we'll brew two cups of coffee for comparison, where one is brewed normally (keeping the coffee liquid), and the other has the blooming coffee liquid discarded. The bean selection, brewing parameters, and technique are unified.

For the beans, we used FrontStreet Coffee's Yirgacheffe Natural Red Cherry for this comparative experiment. This is a very classic natural Yirgacheffe coffee, and FrontStreet Coffee uses medium-light roast to highlight its flavors of berries, citrus, and fermented fruit aroma.

For parameters, we used 15g of coffee grounds with a theoretical water-to-coffee ratio of 1:15, ground to medium-fine pour-over consistency (78% pass-through rate on #20 standard sieve), with water temperature at 91°C. V60 #01 drippers were used for both brews.

Brewing Process

Keeping Coffee Liquid:

First, pour 30g of water for blooming for 30 seconds, then for the second pour, add 95g of water in circular motions from center outward until the liquid level reaches the root of the V60's ridges. When the liquid level drops to halfway, perform the third pour, adding 100g of water in circular motions from center outward. Remove the dripper once all coffee liquid has dripped into the lower pot. Total time: 2 minutes.

Discarding Blooming Coffee Liquid:

First, pour 30g of water for blooming for 30 seconds. At approximately 20-23 seconds, the blooming liquid finishes dripping into the lower pot. Pour this coffee liquid into a container (for later use) and reset the scale to zero. Then for the second pour, add 95g of water in circular motions from center outward until the liquid level reaches the root of the V60's ridges. When the liquid level drops to halfway, perform the third pour, adding 100g of water in circular motions from center outward. Remove the dripper once all coffee liquid has dripped into the lower pot. Total time: 2 minutes.

Flavor Comparison

Keeping Coffee Liquid:

Measured concentration was 1.42%, with distinct layers of berry acidity, fermented fruit aroma, citrus, passion fruit, and other flavors.

Discarding Blooming Coffee Liquid:

Measured concentration was 1.24%, with the weight of discarded blooming liquid being 15.6g. The overall coffee liquid was bland, like drinking water with a slight berry flavor, and the acidity was not prominent.

The previously saved blooming coffee liquid finally makes its appearance. Pour the blooming coffee liquid back into the coffee and shake gently. You can clearly taste the berry and other flavors, and the acidity becomes prominent.

In our daily brewing, the initial coffee liquid is typically the most concentrated, while subsequent pours become increasingly diluted. In fact, the initial blooming coffee liquid contains the most coffee flavor compounds (especially acidity). Keeping it will make the brew more complete and better reflect the full flavor profile of the coffee. Of course, during blooming, we should avoid excessive coffee liquid dripping into the lower pot, as the more coffee liquid that drips into the lower pot, the more it reflects incomplete blooming of the coffee grounds layer (water has only penetrated the surface of the coffee particles).

Important Notice :

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