Brewing tips: What should I do if water accumulates at the end of hand brewing?

I believe many people have had this experience: sometimes when brewing shallow roasted beans, it is particularly easy to accumulate water. When you add water at the end, you will find that the water level drops very slowly and it can't be completely dripped out. The store recommends that you finish brewing within a few minutes. If you wait, you are afraid of over-extraction; if you don't wait, it feels like the taste will be incomplete... This makes hand brewing very stressful and nervous.

Why does lightly roasted coffee tend to accumulate water more easily and flow more slowly? What should you do when you encounter water accumulation at the end of hand-poured coffee? This time, I will share the reasons why lightly roasted coffee tends to accumulate water, as well as the solution for your reference. I hope that after understanding it, you will not misunderstand the beans.

◆High density (shallow baking is heavier)

There are more substances in light roasted coffee, so it is heavier per unit volume, which means it has a higher density, which means it is easier to sink in water~~

Because the roasting temperature and time are shorter, the thermal weight loss of light roasting is less, about 10~13% (that is, 87~90 grams of cooked beans come out of 100 grams of raw beans), while deep roasting can be as high as 18% or more, so light roasted beans are heavier! When the grinding scale of the grinder is the same, we can assume that the volume is the same as a constant: 1. Then the formula for calculating density is: Density = mass ÷ volume

Light baking = (1-0.13) ÷ 1

Deep roasting = (1-0.18) ÷ 1

Things with high density tend to sink easily, so it can be inferred that light-roasted coffee is more likely to settle when brewed, causing the filter pores to become clogged and the flow rate to be slow.

◆Small volume expansion (light baking is more compact and does not expand)

During the roasting process, light roasted coffee expands to a lesser extent, which means that the cavity inside the coffee cell wall is also narrower, and there is not as much space as dark roasted coffee to store the gases produced during the reaction. Just like blowing up a balloon, there is less gas inside so it is more difficult to float.

Compared with dark roasted beans, which have a loose structure and can store more gas per unit volume, the degassing time during brewing is long. Light roasted beans have a compact structure, a higher unit density, less gas storage space, and a shorter degassing time, so they are more difficult to float.

◆Light roasted beans have a finer grinding scale

As mentioned above, lightly roasted beans lose less weight and expand less, so they have a high density and a compact structure. When grinding lightly roasted beans, a finer grinding degree is required than for darkly roasted beans in order to completely extract the flavor molecules of the coffee. The coffee powder particles are fine, and the gaps for water to flow through are also fine, so the flow rate is naturally slow. In the final stage of hand brewing, the amount of coffee liquid that can pass through the powder wall and flow through the filter paper from the side will gradually decrease, and the remaining accumulated water can only flow out through all the coffee powder, so it is easy to accumulate water.

So, what should you do when you encounter water accumulation at the end of hand flushing?

①Discard. The longer the extraction time, the easier it is to over-extract, extracting unnecessary and unpleasant wood fiber flavors, causing bitterness. In fact, most of the essence has been extracted in the early stage. The efficiency of hand-brewed coffee is lower as time goes by, and the less flavor substances can be extracted. Therefore, the part with accumulated water at the end is light in flavor and not very good (if you don’t believe it, you can try to taste the residual liquid yourself). The last part of the light coffee liquid is mainly used to dilute and adjust the concentration, so it is not a pity to discard it. You only need to add some water to the extracted coffee liquid to get the same concentration and taste.

② Adjust the grinding to a coarser level. The main reason for water accumulation is that the grinding is too fine or there is too much fine powder, which clogs the filter paper pores. Therefore, you may wish to readjust the balance in terms of water temperature, grinding degree and stirring. Adjust the grinding to a coarser level, then increase the water temperature, and add appropriate stirring to avoid water accumulation and achieve a similar extraction effect.

③Sieve fine powder. Sometimes the accumulation of water is caused by the poor quality of the grinder, which results in too much superfine powder. So just buy a simple powder sifter on Taobao and sift the superfine powder a little before brewing, which can significantly improve this problem. If you are worried about wasting the sieved superfine powder, you can put it back into the filter cup before the last section of water injection to brew, so that there will be no waste and no blockage~

There are many ways to make coffee taste good. The editor thinks it is also important to understand the logic behind it. Next time you encounter this situation, you might as well drink it first to see if there is anything you don’t like about the flavor, and then define whether there is any room for improvement in brewing!