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How to Adjust Extraction Efficiency in Pour-Over Coffee? Why Baristas Take a Sip of Your Coffee Before Serving?

Published: 2026-01-27 Author: FrontStreet Coffee

Last Updated: 2026/01/27, In the world of coffee, there are always behaviors that seem incomprehensible to outsiders. For example, many people share one cup of coffee, or use a spoon instead of a cup to drink coffee, or make "whooshing" sounds while tasting coffee. Such phenomena leave those outside the coffee circle amazed and bewildered.

In the world of coffee, there are always some behaviors that seem bewildering to outsiders. For example, many people might share a single cup of coffee, drink coffee with a spoon instead of a cup, or make "shushing" sounds while drinking coffee. Such behaviors leave non-coffee enthusiasts feeling puzzled and finding them hard to understand. However, these actions are actually steps or processes designed to better appreciate coffee.

These behaviors mentioned above are relatively uncommon in daily life, since cupping sessions or coffee tasting events aren't happening all the time. But when it comes to the most common behavior that puzzles non-coffee enthusiasts, it's probably this: when you go to a coffee shop and order a pour-over coffee, after the barista finishes brewing, they don't immediately serve it to you. Instead, they turn around and pour a small cup for themselves to taste before handing your coffee to you. Not just outsiders, but FrontStreet Coffee believes that when you first stepped into the coffee world, you must have had the same question: "Why do some baristas pour a cup for themselves to taste before serving a pour-over?"

Why Baristas Taste Coffee Before Serving

Why do baristas pour a cup for themselves to taste before serving a pour-over? To be honest, this behavior is quite simple to explain—it can be summarized in one sentence: to maintain consistency in their brews!

The Complexity of Pour-Over Coffee

Although pour-over coffee might seem relatively simple, there are actually many factors to consider! Subtle changes in the extraction subject (coffee beans) can cause noticeable differences in the taste of the brewed coffee.

Changes in Bean Condition

Freshly roasted coffee beans contain abundant carbon dioxide. Excessive carbon dioxide reduces extraction efficiency, preventing hot water from adequately extracting the flavor compounds from the coffee. Fortunately, carbon dioxide doesn't remain in coffee beans indefinitely.

It continuously and slowly escapes through the porous shell of coffee beans that were "riddled with holes" during roasting. Because of this, the condition of coffee beans changes daily. When brewed using the same method, the same coffee beans might produce different flavors just a few days apart. Due to varying carbon dioxide content in the beans, the extraction efficiency differs even when other parameters and methods remain unchanged, leading to taste variations.

Therefore, baristas need to taste the coffee first to determine whether the extraction rate is adequate and whether the concentration is appropriate before deciding to serve it to customers. If they discover irreversible negative effects in this small sample, such as under-extraction or over-extraction, the barista will choose to remake the coffee until it meets quality standards before presenting it to the customer.

Barista remaking coffee for quality control

FrontStreet Coffee's Approach

However, customers who frequently visit FrontStreet Coffee will notice that FrontStreet Coffee doesn't have a step of pouring out a small cup to taste before brewing pour-over coffee for customers. It's not just FrontStreet Coffee—many coffee shops follow the same practice. Why? Because ultimately, what causes the variation is the constantly changing state of coffee beans. As long as we learn how to control extraction efficiency during brewing according to the beans' current condition, we can maintain a consistent flavor in our brewed coffee.

How to Ensure Consistent Coffee Quality

Before that, we need to first select a set of suitable brewing parameters based on the beans' roast level and processing method—this is essential! Choosing the right brewing parameters is like establishing a solid extraction foundation. No matter how the substances within the beans change (within their best-by period), the flavor of the brewed coffee will only be slightly affected, staying within a stable range.

To minimize the impact of carbon dioxide, as mentioned earlier, we need to learn how to control extraction efficiency during brewing based on the beans' condition!

The appearance of the coffee bed during blooming and the speed of water flow can both serve as objects of observation! For example, when the coffee bed indicates that the beans are in a relatively "fresh" state, it means higher extraction efficiency is needed for extraction, because the presence of carbon dioxide increases resistance to extraction! In this case, we can manipulate the water flow to extend extraction time, allowing hot water to achieve higher extraction efficiency and reduce the impact of excessive carbon dioxide.

If the coffee bed appears less "active" (meaning the beans have been stored for a longer time), we can shorten extraction time to prevent over-extraction due to other parameters resulting in excessively high extraction efficiency. Additionally, there are other details to pay attention to, but overall, it's about learning to adapt flexibly.

The main concern should be beans outside their optimal tasting period, as the variation in beans within their optimal period isn't actually too significant. Stable brewing with consistent parameters can reliably produce delicious coffee. So, as mentioned before, as long as you fully understand coffee extraction principles, you can skillfully brew delicious coffee regardless of how the beans change.