What do you mean by pass? Why do you need to "re-mix"or "re-hydrate"coffee?

Coffee is accidentally made too strong and tastes concentrated and exciting, which is a common problem faced by many newcomers who are beginners to brew. Out of the mentality of not wanting to waste, we usually want to mix it with water, just like the cooking ideas of other dishes, hoping to save the pot of coffee by diluting the concentration.

In fact, this method does have a technical term in the coffee industry, called "By pass", which translates into Chinese to mean "bypass". When it is applied to the manual extraction frame, the coffee liquid obtained by washing the coffee powder is the "right way", while By pass is the hot water that bypasses the coffee powder and goes directly to the cup, so this part of the hot water that is not involved in the extraction is also called "bypass water". When extracting with a V60 filter cup, the hot water spirally flowing along the side wall to the next pot also belongs to "bypass water" because it does not pass through the coffee powder. )

For example, American coffee, which we are all familiar with, is the most commonly used By pass. The purpose of adding water is very simple, that is, to adjust the concentration, so to some extent, it is actually "dilution".

In some professional coffee competitions, contestants also use By pass to interfere with the brewing frame in order to avoid the risk of bitterness in the end of some beans. It is often used in some high-concentration and low-extraction brewing schemes, that is, a pot of high-concentration coffee liquid is flushed out with a relatively large amount of powder or a low powder-to-water ratio, and then hot water is directly added to coordinate the concentration.

To put it bluntly, it is to use the extraction law of strong coffee first and then light coffee to better handle the ideal flavor performance, but this operation often requires 2-3 times coffee powder to make a cup of coffee, so the disadvantage is that it costs too much beans.

For example, we usually do ice hand flushing is also a very typical By pass idea, but here the original hot water will be replaced with ice. For example, if the amount of powder produced in front of the hot hand is 15 grams, and the proportion of powder to water is 1:15, the ice hand will be brewed at 1:10, that is, the empty 75 grams of hot water will be replaced by 75 grams of ice "reserved" in the pot in advance, and then filled with water according to the proportion of the plan. while cooling the coffee liquid, it also dilutes the original high concentration, so as to get a cup of iced coffee with the right concentration.

Of course, in addition to the above expected operations, By pass also has a certain "remedial" function.

For example, Qianjie used to 15 grams of coffee powder, according to 1:15 powder ratio to brew a pot of Panama 90 + Manor Juliet Rose Summer, but accidentally adjust the grinding degree to half a lattice (EK43s scale 9), although the coffee also has obvious fermented wine and cocoa flavor, but almost can not feel any bright acidity, the overall taste is low and thick, lack of layered sense. As a result, Qianjie added about 10 grams of 80 ℃ warm water to the coffee liquid, shook it evenly and tasted it again, the acidity of grape juice became clear, along with the sweetness of preserved fruit, the taste was much lighter.

Fine grinding accelerates the release of all soluble substances into the coffee liquid, and caramelized flavors such as cocoa and spices make it impossible for taste buds to distinguish other light aromas, so the "bypass water" can help us open the entire taste spectrum. from which we can perceive the lighter ingredients, thus making the coffee more layered.

Different from the remedial situation afterwards, when By pass is used as a flexible means when the flow velocity is abnormal, it will test whether the brewer can make a decision immediately.

An article in Qianjie once mentioned that when roasting coffee, fine grinding and high hardness particles are easy to cause stagnant water in the later stage of mixing, prolong the soaking time of coffee powder, and accordingly increase the probability of over-extraction. Therefore, when the extraction time is more than 2 minutes and 10 seconds and the coffee liquid is not finished, we can judge based on experience and consider removing the filter cup and abandoning the tail section, then taste whether the taste is too strong, and then add a small amount of hot water in the pot (5g / 10g) until it suits our own taste.

It should be noted that since bypass water is not in the extraction plan, blindly mixing it directly will not only dilute the original positive flavor, but may also make coffee as light as water, so Qianjie suggests shaking and tasting every time after adding bypass water, and then determine whether to continue to add, so as not to dilute to an irreversible degree.

In addition, if we brew a cup of coffee according to the normal parameters and find that its concentration is fine, but its aroma is average, accompanied by a negative taste such as bitterness, astringency or sticking throat, then this pot of coffee may have caused irreversible excessiveness. the influencing factors are usually uneven coffee powder, low performance of the bean grinder, too much very fine powder, and unstable flow control. At this point, the addition of bypass water will not help, or even make it more like coffee-flavored water.

I believe that when you see this, you should be able to guess that there is no reference standard for this method of "replenishing water" in operation, and it is more likely to add water bit by bit in actual combat according to a certain god's idea of brewing and cooking, until the sensory experience is satisfied. There is a certain element of "adventure". Therefore, for beginners, Qianjie does not recommend the blind use of By pass intervention extraction, if the taste of coffee is really wrong, we should carefully review where the problem comes from, instead of always relying on "hydration" to save it.

-END-

Front Street Cafe

No. 10 Baoqian street, Yandun road, Dongshankou, Yuexiu district, Guangzhou, Guangdong province