What is foam-observation pour-over method?
1. Why not use a fixed coffee-to-water ratio?
Traditional pour-over brewing usually relies on a fixed coffee-to-water ratio (like 1:15) to achieve a stable extraction effect; however, this method may limit the expression of different coffee bean flavors. The principle of the foam-observation pour-over method is to adjust extraction to the beans’ characteristics and current condition, using changes in the foam to guide these decisions.
Regarding this method, the coffee beans that are too fresh (within one week after roasting) are not suitable, because at this time the beans contain a large amount of carbon dioxide, which can produce a large amount of white foam during brewing, making it impossible to accurately control the extraction conditions. Similarly, coffee beans that are too old (stored for over a month) are also unsuitable, because the carbon dioxide has dissipated, making it impossible to produce sufficient foam.
2. Advantages of the foam-observation pour-over method
During this period, I tried multiple different dates of coffee beans and found that the foam-observation method can adjust coffee flavor more flexibly than a fixed coffee-to-water ratio. This method is like the chef controlling the doneness of the beef steak, observing changes in the foam to understand the extraction condition of the coffee beans, and also adjusting according to the required output. This way of brewing can more accurately present the flavors of coffee beans at different time segments, achieving the best extraction effect.
3. Recommended brewing parameters
The unique feature of the hand brewing method is not to be limited to a fixed coffee-to-water ratio but to adjust the number of pours based on the desired flavor. Below are my suggested brewing parameters:
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Coffee bean amount: 13 to 20 grams, depending on personal preference, I usually use 20 grams.
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Number of pours: You can divide the pours using the concept of the 4:6 pour-over method, I personally believe that a 4:6 method can achieve a relatively balanced flavor.
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Water technique: Use a small circle to pour water in the center, raising the foam is crucial for observing extraction. If the foam does not rise, it is not possible to judge the current extraction accurately.
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Pre-wet and main water: First pre-wet for 40 grams of water, then pour water into the small center circle to 130 grams, maintaining a fine to medium water flow throughout the process.
When the water has nearly drained through, observe changes in the foam and decide when to stop pouring for the flavor you want.
How to observe coffee extraction through the foam
The essence of the hand brewing method lies in determining the extraction degree through the color and condition of the foam during brewing. Changes in the foam at different stages can indicate the release condition of your coffee flavor, which also gives you more control over the final flavor adjustment.
Through this period of practice, I believe this method is very effective, regarding aroma, overall flavor performance, and aftertaste all have obvious improvements. Although this may allow some flavors to change to become more prominent, while losing some balance, but this is a worthwhile method to try, especially for coffee lovers who enjoy challenges and exploring new flavors.
Brewing operation steps
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Step 1: Prepare 20 grams of coffee beans, proceed to pre-wet 40 grams.
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Step 2: Start pouring water from the small circle, gradually pouring to 130 grams.
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Step 3: Maintain a fine to medium water flow, observe changes in the foam and decide when to stop pouring for the desired flavor.
Each person's preference for flavors is different, so you can adjust the brewing method and parameters based on your own taste. Friends who are interested can try this method next time they brew coffee and see if it brings a delightful flavor experience.
Frequently Asked Questions (Q&A)
Q1: Is this method suitable for all coffee beans?
A1: Not entirely suitable. The foam-observation pour-over method works best with beans roasted 1-3 weeks ago. If the beans are too fresh (within one week after roasting) or too old (stored for more than a month), the results will be poorer because their carbon dioxide content is outside the ideal range.
Q2: Why not use a fixed coffee-to-water ratio?
A2: A fixed coffee-to-water ratio can limit the expression of the beans’ characteristics. The foam-observation method adjusts pouring according to the foam, allowing more layers of flavor to emerge.
Q3: How can you tell whether the foam is in the right condition?
A3: The ideal foam should be stable and finely textured, with its color gradually changing during extraction. Observing the foam’s color and thickness can help you determine if you have reached the desired extraction level.
Q4: Does the foam-observation pour-over method require special equipment?
A4: No special equipment is needed. You can use a regular pour-over kettle and dripper, focusing on controlling the flow of water and observing the foam.
Q5: Is this method suitable for new brewers?
A5: This method may pose some challenges for new brewers, as it requires extraction adjustments based on changes in the foam. However, for friends who want to improve their brewing skills, this is a technique worth trying.
Q6: How does the foam-observation method taste different from traditional pour-over?
A6: The foam-observation pour-over method allows for more flexible control of the coffee's flavor, making the aroma richer and the aftertaste deeper. However, some flavors may emerge more abruptly, which could affect the overall balance of the brew.
