When we use three-stage extraction, it means that the target water has to be injected in 3 times during the whole pour-over process, that is, first filling, waiting, then filling, then filling, and finally waiting for all the coffee droplets to be filtered.
Take the 15 grams of powder commonly used in Qianjie with a 1:15 powder-to-water ratio as an example, the total amount of water poured is 225 grams, and 30 grams of water simmering for 30 seconds is the first stage that many people have reached a consensus on, so the remaining 195 grams of water will be injected into two parts successively. So the question is, how should these two parts of water be distributed reasonably? Will the difference in the amount of water in each section affect the flavor of the coffee? With curiosity, let's focus on this question today: in a three-stage framework, if the steaming formula remains unchanged, how will the allocation of water in the second and third stages affect the flavor of the coffee.
Considering that the trend of coffee flavor is the main basis for judging the final result of this water allocation experiment, the medium roasted Qianjie 2013 iron picker is selected as the brewing object, which has both the sweetness of chocolate, the acidity of berries and the sweetness of brown sugar, which is more conducive to us to intuitively feel the change of coffee flavor under the adjustment of water volume.
Coffee beans: Front Street 2013 Yunnan small grain iron truckPowder weight: 15 gramsTotal water volume: 225 gramsGrind: 10 scales of EK43Water temperature: 90Bowl: Resin V60In addition to the 30 grams of smothering water, the remaining 195 grams of water will be divided into 3 groups to carry out
no.1 The second stage (125 g) > the third stage (70 g).no.2 Second paragraph (975 grams) = third segment (97.)5 grams).no.3 The second paragraph (70 grams) and the third paragraph (125 grams).
In order to minimize the impact of human factors, the starting water filling time of the three groups is also the same, which is 1 second - 30 seconds - 1 minute 06 seconds. In the end, the time points of the three groups of drip filtration were 2 minutes and 10 seconds, 2 minutes 03 seconds and 2 minutes 05 seconds, respectively, and the time difference was not large. Since the three groups of hand punches are extracted in order, there is a certain temperature difference, which also affects the perception of sweet and sour, but Qianjie still feels the subtle difference. In terms of flavor and taste, the three pots of coffee all present a relatively balanced tonality, that is, there are sour, sweet and bitter, and they are all rich in hazelnut, cocoa aroma and brown sugar aftertaste, but in the details of acidity, body and aftertaste, the three pots of coffee show different effects.
The first group: In the middle temperature stage, the black brin-like acid is the strongest, and the caramel sweetness is shown with the decrease of temperature, but the body is the thinnest;
The second group: The taste is the most balanced, the aroma is also the most solid, the overall flavor is round and thick, and there is less lively fruit acid than the first group;
Group III: There is a heavy black tea feeling in the mouth, almost acid-free, the bitterness is the most obvious of the three pots of coffee, and it is slightly astringent after cooling, so I guess it is slightly over-extracted.
During the formal filling phase after steaming, the water flow allows the ground coffee to stir and tumble in the filter bowl, which in turn improves the extraction efficiency of the flavor compounds. When the extraction efficiency is increased at different times, different flavor effects will occur. Going back to the three-stage formula, that is, the more water is distributed in a certain section, the more the extraction efficiency of the soluble flavor substances in this section can be improved. For example, in the first group of experiments, because the amount of water allocated in the early stage is more, the liquid level piles up the powder wall, and the acidic substances can be released in large quantities at this stage, so that the coffee shows a lively and upward acidity. At the same time, the amount of water in the later stage is too small, and the liquid level cannot reach the height of the second stage of the powder wall after injection, in other words, this part of the particles cannot participate in the third stage of extraction, resulting in a thin body.
The third group of experiments was the opposite, the second stage of water was allocated less to raise the powder wall to only 1 2 places of the filter cup, and the sour substances did not have time to be released, and the powder layer was overflowed by the third stage with a larger amount of water. Not only does it allow some of the hot water to slip away directly from the ribs, but the fine powder also slides along the edges to the bottom and is soaked in hot water, increasing the release of macromolecules (bitter substances). To sum up, Qianjie believes that in the planning of a three-stage water allocation, in addition to considering the flavor direction of the coffee beans, the height of the water level of each section should also be combined. For example, when brewing light-roasted coffee beans that mainly express the floral and fruity sour flavor, you can appropriately increase the water distribution in the second stage, and at the same time observe the sedimentation rate of the water level and inject the remaining water.
For example, when brewing Panama Poquette Geisha on Front Street, a sectional plan of 30 grams (steamed) in the first section, 120 grams in the second section, and 75 grams in the third section will be used, and the water filling time of the last section will be judged according to the height of the liquid level, and the reference position is that the water level drops to "1 2 of the powder wall". This gives the coffee a high-rise fruit acidity without losing the caramel-creamy taste and finish.
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