Exploring Coffee Flavours Through the V60 Pour-Over Method: A Deep Dive Into Extraction
At Fission and Bloom, we’re passionate about uncovering the complexities behind every cup of coffee. One of the most fascinating aspects of brewing is how different flavours are extracted at various stages of the process. In our latest YouTube video, we demonstrated this using the V60 pour-over method, and now we’re diving deeper into how you can experience this for yourself at home—plus some science behind the extraction process.
Understanding Coffee Extraction
When brewing coffee, the extraction process determines the flavours you’ll taste in the cup. The type of flavours extracted changes throughout the brew—starting with tart and acidic notes, followed by sweetness, and eventually leading to more bitter, flat flavours as the brewing finishes.
We used the V60 pour-over method to demonstrate this in a simple yet effective way by splitting the brew into four stages. Each stage captured a different part of the extraction process, showing how time, water, and grind size impact the final taste.
The Role of Water-to-Coffee Ratio in Flavour Balance
One crucial aspect of brewing coffee is finding the right water-to-coffee ratio. This ratio is important for achieving both the right extraction yield and a balanced flavour profile. A higher coffee-to-water ratio results in a stronger coffee, but not necessarily a more bitter one. Instead, the coffee will have a darker, thicker mouthfeel due to the increased concentration of solids and oils.
As water moves through the coffee bed, different flavour molecules are extracted at different times, with some compounds being more soluble than others. For example, highly soluble compounds like caffeine, sugars, and organic acids are extracted early in the brew, resulting in a cup that is dominated by sweet and acidic flavours. This is why under-extracted coffee often has a sweeter-acidic profile.
As the brewing continues, less soluble compounds—many of which contribute to bitterness and astringency—begin to dissolve. Compounds such as phenylindanes and chlorogenic acid lactones are extracted later in the process (or, for some of these compounds, continuously, but become more perceivable), and these give rise to the stronger, more bitter flavours we associate with over-extraction. This shift in the flavour balance explains why long cups tend to taste more bitter and harsh.
How We Demonstrated Flavour Changes
In the video, we started by brewing 15 grams of speciality coffee ground to a medium-coarse setting. We used the V60 dripper, a well-known method for producing a clean, balanced cup. To show how flavours shift during extraction, we divided the brewing process into four distinct sections:
First Cup (Tart and Sour Flavours)
After pouring the first 50 grams of water, we let the coffee extract for about a minute. This first cup is where the sour and tart flavours dominate. These are the lightest and most acidic compounds in the coffee, and they come out early in the brewing process.Second Cup (Slightly Less Sour)
The second pour was another 50 grams of water, continuing the extraction. This cup still had tartness, though it was less pronounced than the first. This stage is where you can still detect acidic flavours, though they’re beginning to mellow.Third Cup (Sweetness and Balance)
The third cup, brewed with an additional 50 grams, brought out a major shift in flavours. Here, the coffee revealed its sweeter, chocolatey notes, and the sourness disappeared. This is where the brew begins to reach its balanced middle.Fourth Cup (Bitterness and Flat Taste)
By the fourth and final pour, the coffee had lost much of its intensity and had a weak, flat taste with hints of bitterness. This is typical in the later stages of extraction, where the heavier, less pleasant compounds are released.
Combining the Flavours
After tasting each individual cup, I combined all four into one. The result? A well-rounded, complex cup of coffee. By blending the stages of the extraction, you can create a balance between acidity, sweetness, and bitterness. The result is a more harmonious flavour profile that brings together the best of each stage.
Experimenting with Grind Size
To take things a step further, I tried the same experiment but with a coarser grind. This introduced another interesting dynamic:
The first cup was less sour than the finer grind, while the second cup became more sour and tart.
The third cup remained sweet, while the fourth cup was again weak but had a slightly sweeter, less bitter aftertaste than before.
This shows that grind size plays a crucial role in how flavours are extracted. Adjusting the grind can highlight or diminish certain characteristics in your coffee, allowing you to tailor your brew to your preference.
The Science Behind Coffee Extraction
The process of coffee extraction is influenced by solubility and the structure of coffee particles. Highly soluble compounds like caffeine, sugars, and organic acids dissolve early in the brewing process, which is why under-extracted coffee tends to be dominated by sweet and acidic flavours.
On the other hand, less soluble compounds—such as phenylindanes and chlorogenic acid lactones—take longer to dissolve. These compounds contribute to the bitterness and astringency found in over-extracted coffee. As a result, longer extraction times, which can be achieved with a finer grind size, shift the flavour profile from sweet and acidic to bitter and harsh.
To avoid over-extraction, you can stop the brewing process early and dilute the coffee with hot water if needed. This prevents the extraction of too many bitter compounds while preserving the balance between sweetness and acidity.
What This Means for Your Coffee Experience
This experiment reveals that the brewing process is not just about time—it’s about managing flavour extraction at every stage. Whether you prefer a more acidic cup or a balanced, sweet brew, understanding how coffee extracts over time can help you control the flavour and body of your cup.
The V60 pour-over method is ideal for experimenting with these stages. It gives you more control over water flow, timing, and grind size, making it a fantastic tool for coffee lovers looking to deepen their appreciation of the brewing process.
Try This at Home
If you want to taste the nuances in your coffee, try this experiment at home with your own V60 dripper. Split your brew into sections and see how the flavours change. You might be surprised by how different each part of the extraction can taste!
Remember, small adjustments—whether in grind size, water temperature, or timing—can make a huge difference. It’s all part of the joy of brewing coffee, discovering what works best for you and creating a cup that’s truly your own.
At Fission and Bloom, we believe in exploring the full potential of every coffee bean. Stay tuned for more experiments, tips, and advice on brewing the perfect cup.
