Mastering coffee extraction is one of the most rewarding yet challenging aspects of drip coffee brewing. With numerous factors at play—grind size, coffee-to-water ratio, and water temperature—perfecting the process can result in a truly exceptional cup.
To gain a deeper understanding of extraction and how to improve your brew, it’s helpful to explore the concept of the three phases in drip coffee brewing. I had the chance to discuss this with Patrik Stridsberg, Co-Founder of 3TEMP, and London-based coffee expert Will Corby. Here’s what I discovered from our conversation.
The Pre-Brew (Bloom)
The pre-brew, commonly referred to as the “bloom,” marks the initial phase of drip coffee brewing. In this step, a small amount of water is poured over the grounds, just enough to moisten them, and you let it sit for about 30 seconds. The primary purpose of this phase is to release trapped carbon dioxide (CO2).
During the roasting process, CO2 gets locked inside the coffee beans—especially in lighter roasts, which hold onto more gas than darker ones that have already released much of it during the second crack. As the coffee degasses over time, some CO2 remains, and it is released when the grounds come into contact with hot water, creating the bloom. The greater the gas buildup, the more pronounced the bloom.
This step improves your coffee in two key ways. First, CO2 imparts a sour taste that you want to avoid in your cup (remember, there’s a distinction Drip Coffee Brewing between bright acidity and unpleasant sourness). Second, as the grounds release gas, this gas can push water away from the coffee, hindering proper extraction. By allowing this to happen during the bloom, rather than during the main brewing process, you ensure more consistent flavor extraction throughout the brew.
Extraction
The extraction phase is where you begin to shape the flavor profile of your drip coffee brewing. As water interacts with the coffee grounds, different compounds are extracted at various stages. Initially, bright and fruity acids are released, followed by sweet flavors, and finally, bitterness. It’s important to note that not all acids contribute to the desired fruity acidity—caffeoylquinic acids, for instance, can cause bitterness and astringency. In this context, we’re focusing solely on the pleasant, acidic notes that enhance the coffee’s flavor.
Because these compounds extract at different times, you can control the brewing process to achieve the ideal flavor balance. The two main factors that influence this are water temperature and brew time. Typically, the optimal water temperature ranges from 91°C to 96°C (196°F to 205°F), but variables such as roast level, coffee freshness, and grind size can impact the ideal brewing temperature.
Patrik also highlights the importance of “pulsing,” which refers to the technique of using multiple smaller water pours during the brewing process. While some argue that reducing the number of pours simplifies the process and leads to more consistent results, Patrik believes that pulsing is key to enhancing extraction efficiency. His company’s brewer, the Hipster, even features programmable pulsing for better control. Fewer, larger pulses can shorten extraction time, while more frequent, smaller pulses can extend it and ensure a more even coffee bed. The ideal pulsing pattern depends on the grind size and the characteristics of the coffee being used.
The Final Stage of Drip Coffee Brewing
The “end phase” refers to the final 40% of the drip coffee brewing process, where careful control is crucial. This is when the most bitter compounds are extracted, and if over-extraction occurs, it can ruin the flavor of your coffee.
Patrik emphasizes that managing both brew time and water temperature at this point is essential. By lowering the water temperature during the end phase, you reduce the extraction rate, which helps maintain a well-balanced, sweet, and slightly acidic cup. In pour-over brewing, you don’t need to worry much about this as the water naturally cools over time. However, when using an automatic or batch brewer, adjusting the brew temperature can significantly impact the result.
For example, Patrik’s Hipster brewer is programmed with default settings that start with a pre-brew temperature of 97°C (206.5°F), followed by 94°C (201°F) during extraction, and then dropping to 89°C (192°F) for the end phase—5°C lower than during the main extraction. While he advises tweaking these settings based on the specific coffee you’re using, this gradual reduction in temperature typically leads to a balanced, fruity, and sweet brew.
Whether you’re making a single cup or brewing a large batch, understanding and controlling the different phases of drip coffee brewing—especially the temperature—can greatly improve your coffee’s flavor.