Pour-Over Coffee Three-Stage Pouring Technique Algorithm: How to Determine the Right Timing for Water Flow Interruption

Some friends have asked FrontStreet Coffee, "FrontStreet Coffee, for the three-stage pour-over, should I wait until all the water has drained before adding the third pour, or should I pour when it's halfway drained? Why do some people say it's better to wait until all the water has drained?"

This friend asked FrontStreet Coffee this question because when FrontStreet Coffee teaches coffee brewing, we do not recommend waiting until the coffee liquid has completely drained before pouring. So what's the difference between these two pouring methods? You can see FrontStreet Coffee's comparison of two brewing methods. You can also brew and compare them yourself, which would be more intuitive.

First Brewing Experiment

First, FrontStreet Coffee used Costa Rica Strawberry Candy coffee beans for brewing. The brewing parameters followed FrontStreet Coffee's standard parameters:

Coffee dose: 15 grams
Ratio: 1:15
Grind size: 80% pass-through through #20 sieve
Water temperature: 90°C
Dripper: V60
Brewing method: Three-stage pour

The difference between the two groups was that the first group followed FrontStreet Coffee's regular brewing method, starting the third pour when the water level dropped to half; the second group only started the third pour after the water level had completely dropped and drained.

The two groups were basically consistent in the early stages. The second pour was completed at 54 seconds (total water poured at this point was 150ml). The first group started pouring when the water level dropped to 1/2, with the third pour starting at 1 minute 7 seconds. After finally pouring to 225ml, the time for all water to finish draining was 1 minute 55 seconds.

The second group waited until all the coffee liquid had drained before starting the third pour, at a time point of 1 minute 20 seconds. After the third pour to 225ml, the time for all water to finish draining was 2 minutes 10 seconds.

In terms of aroma, the first group was richer. During tasting, the flavors of both groups were basically the same, with no negative flavors.

From this experiment, we see that these two methods don't have significant differences. Because the second group had to wait until all the coffee liquid had drained before pouring, the coffee grounds in the filter experienced a "flow interruption," which caused a brief sudden temperature drop in the coffee ground layer. The temperature only rose again when continuing to pour later. This is what caused the difference in aroma richness.

Also, because waiting for the coffee liquid to completely drain before pouring takes longer than pouring when the water level drops to 1/2, the final extraction time is correspondingly longer. However, the extraction time in this experiment was within a reasonable range, and the flavor performance was also good.

Second Brewing Experiment

Now let's look at a second experiment. The comparison method was exactly the same, but the brewing beans were changed to washed Yirgacheffe. Let's see how this experiment's results turned out.

Both groups completed the second pour at 54-55 seconds (total water poured at this point was 150ml). The first group started pouring when the water level dropped to 1/2, at a time of 1 minute 10 seconds. After the third pour to 225ml, they waited for all the coffee liquid to drain completely to finish extraction, at a time of 2 minutes.

The second group waited until all the coffee liquid had drained before starting the third pour, at a time of 1 minute 30 seconds. After injecting the third pour, they waited for all the coffee liquid to drain completely to finish extraction, at a time of 2 minutes 30 seconds.

In this experiment comparison, the second group coffee showed bitterness. Why was there such a large time difference in the group that waited for the coffee liquid to drain completely before pouring between these two experiments? The reason lies in the coffee bed.

By observing the Yirgacheffe coffee bed, we can see there's quite a bit of mud-like consistency at the bottom. This "mud" is actually fine particles. We've mentioned before the characteristics of the V60 dripper - when the water level reaches the short ribs, there are 24 flow ribs guiding water into the lower pot. This ensures good drainage speed. When the water level drops below the short ribs, only 12 flow ribs remain. At this point, if there are fine particles in the coffee layer, they will slow down the drainage speed. Pouring when the water level drops to half avoids extending the time too much.

So why did this situation occur with Yirgacheffe but not with Strawberry Candy? This is related to the hardness of the coffee beans. Yirgacheffe has a lighter roast degree, corresponding to harder bean texture. During grinding, the whole beans are often not cut into particles at first, but rather crushed by the burrs. This process produces some dust. Coffee beans with lower hardness have fewer instances of being crushed and therefore produce less dust.

Therefore, FrontStreet Coffee does not recommend waiting until all the coffee liquid has drained before continuing to pour in staged brewing. First, the extraction temperature changes. Second, fine particles may deposit at the bottom, causing slow drainage and extending extraction time. Third, brewing parameters have poor universality between different coffee beans.

Of course, this doesn't mean the method of "waiting for coffee liquid to drain before pouring" cannot be used. For example, one could redesign a brewing method to avoid the "defects" FrontStreet Coffee mentioned, like the "4:6 brewing method" by adjusting to a coarser grind, or by sifting out the fine particles from the coffee, or by using different water temperatures for brewing.

However, if you're using the three-stage method to brew coffee, it's better not to wait until the coffee layer is completely dry before pouring.

Important Notice :

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FrontStreet Coffee Address: 315,Donghua East Road,GuangZhou

Tel:020 38364473