What does By pass mean in coffee? What does bypass water refer to in pour-over coffee? Is By pass just adding water to coffee? Is Americano just espresso diluted with water?

Understanding Coffee Terminology: The Concept of By Pass

Like any other industry, coffee has its fair share of professional terminology. We can understand these specialized terms as condensed expressions of complex concepts. They not only improve our communication efficiency but also increase precision while reducing the likelihood of communication barriers.

However, since most terminology isn't particularly intuitive, outsiders or newcomers to the coffee world may struggle to understand their meanings based solely on literal interpretation. Take "By pass" for example. Directly translated, "By pass" means "旁路" (bypass) or "绕路" (detour). Just from the literal meaning, it's indeed difficult to understand what it represents in coffee context. FrontStreet Coffee often shares this term, which primarily refers to water that joins coffee through "bypassing" and the corresponding actions. So what exactly is bypass?

First, we need to understand that water is our solvent when extracting coffee. By allowing water to contact coffee, it dissolves flavor compounds from the coffee, ultimately becoming coffee that lands in our cups. However, sometimes the water we use to make coffee doesn't all pass through the coffee grounds—it "bypasses" the coffee grounds and directly falls into the cup to join the coffee.

If we consider the path where water passes through coffee grounds before reaching the cup as the "main road," then water that reaches the cup without passing through coffee grounds takes the "bypass." This water that takes the "bypass" without participating in extraction is called bypass water. The appearance of bypass water can be both intentional and unintentional! Unintentional examples are often mentioned when FrontStreet Coffee shares brewing techniques. For example, when using drippers like the V60.

When we brew coffee using drippers with numerous ribbing like the V60, we need to avoid letting water levels submerge the coffee grounds. Because the prominent ribs create space for air release, generating more channels for water flow. If hot water submerges the coffee grounds or splashes on the filter paper, this hot water might flow directly through these channels into the cup without contacting the coffee grounds or participating in extraction. This is unintentionally generated bypass water. Its appearance not only reduces the coffee extraction rate but also affects the already extracted coffee liquid, diluting its concentration and diminishing the coffee's flavor and mouthfeel.

There are many examples of bypass water that we intentionally control and generate, with the most classic being "Americano coffee." The process of making Americano involves adding a certain amount of water to extracted espresso. The water added afterward to the coffee is bypass water. The purpose of intentionally generating bypass water is simple—to "dilute" the coffee's concentration. Americano coffee emerged because Americans found straight espresso too concentrated, so they needed to add water to dilute it, making it easier to drink. This behavior of intervening in coffee flavor by adding water can be called By pass.

Besides espresso, By pass is also used in other coffee-making methods, such as pour-over coffee. In professional coffee competitions, we often see contestants using By pass to intervene in their brewing framework. To reduce bitterness in coffee, they might use a high-concentration, low-extraction approach to brew coffee with higher concentration but less bitterness. Because the coffee concentration is too high and difficult to drink, they use By pass to dilute the coffee concentration to a palatable level before presenting it to competition judges.

In daily life, we also frequently use By pass when brewing coffee, though we might not realize it! This is because when we use By pass, we don't directly add water but ice cubes. That's right! FrontStreet Coffee is referring to iced pour-over coffee. When brewing iced pour-over coffee, we need to add ice cubes to lower the coffee's temperature. As the ice cubes cool the coffee, they melt into water, diluting the coffee. Therefore, this is also a By pass behavior because it involves adding water that didn't participate in extraction to the coffee.

Of course, sometimes By pass can also be a remedial measure. For example, when FrontStreet Coffee used the wrong water-to-coffee ratio while brewing FrontStreet Coffee's Boundary Estate·Sidra, the resulting Sidra had very intense flavors that couldn't fully express themselves due to concentration. In situations like this, we can use By pass to appropriately dilute the coffee. Adding just 15-30ml of hot water can reduce the coffee's concentration, allowing the coffee's flavors more room to express themselves, enabling us to better taste the coffee's flavor profile.

Alternatively, when brewing an unfamiliar coffee bean, fine particles might clog the filter paper, preventing hot water from filtering through for an extended time. If this continues, we might end up with an over-extracted coffee full of bitterness. In such cases, we can use flow interruption to discard the coffee liquid still in the dripper that hasn't filtered through. The resulting coffee might not be exceptionally good, but at least it won't be unbearably bitter. This flow interruption results in coffee with higher concentration, so in such situations, we need to use By pass to dilute the coffee until it reaches a palatable concentration.

In summary, we can understand that By pass primarily refers to water that joins coffee without participating in extraction and the corresponding behaviors. However, everyone should note that By pass is not a universal solution for coffee improvement. The cases FrontStreet Coffee shared above all require certain preconditions before using By pass to optimize coffee! If used when the coffee doesn't have problems, we could easily make a coffee with unremarkable flavor and mouthfeel. This is something worth noting for everyone.

- END -

Important Notice :

前街咖啡 FrontStreet Coffee has moved to new addredd:

FrontStreet Coffee Address: 315,Donghua East Road,GuangZhou

Tel:020 38364473