Percolation Brewing

Bloom

The main goal of blooming is to quickly degass the coffee. The CO2 generated during the roasting process will otherwise generate bubbles, which insulates solubles (decreasing yield) and contributes to channeling (decreasing uniformity of extraction). The blooming phase doesn't need to prioritize high yields - as to not release aromatics too early - so some professionals advocate for a cooler bloom, that is around 60~70 °C.

Recipes

Matt Winton's Five Pours ~ James Hoffman's Single Cup V60

A simple 5-pour recipe for medium-coarse grinds that makes use of high agitation. Popularized by Matt Winston (MW1, MW2) and recommended for single-cup brews by James Hoffman (JH1).

• 15 g of coffee
• 250 g of water
• Medium-fine grind, aiming at a 3m total drawdown

1. Bloom with 50 g of water, swirl and rest until 1:00
2. Pour another 50 g, rest until 1:00
3. Pour another 50 g, rest until 1:20
4. Pour another 50 g, rest until 1:40
5. Pour the remaining 50 g and swirl

Kissaten Coffee Dome - 喫茶店 コーヒードーム

An unnamed and very pretty technique traditional in Japanese coffee shops, divulged by Brewing Habits. Sometimes called Osmotic Flow by CAFEC's marketing, though the science justifying that name is controversial.

• Minimum 18 g coffee dose, darker roasts preferred
• 1:13 to 1:16 ratio, traditionally closer to 1:13
• 80-85 °C water is enough for such high dose and darker roast
• Minimize stirring by pouring very slowly and very close (about 1 cm high)
• Grind size about a bit coarser than a normal V60 grind to speed up flow

1. Bloom with 2-3 x dose in slow spirals (10-30 seconds rest)
2. Pour at the center up to 1/3 of the total brew (let it drain for 5 seconds)
3. Pour the remaining 2/3 in a slow spiral up to a ~2.5 cm diameter
4. Let it drain only for 5 seconds, then remove brewer interrupting drawdown

Bypass

It's when water goes around the beans, instead of through. The higher the water level relative to the coffee bed, the more bypass in a regular filter.

No-Bypass Filters It's a concept around pour-over coffee.

Some of the water goes side-ways in the filter and around the coffee. That water is called bypass water.

The more water goes through coffee, the more solubles down the cup. Less bypass means more effective and efficient extraction. A stronger extraction.

Aeropress is zero-bypass, espresso as well. But water doesn't want to go through coffee, it takes pressure.

Models: Tricolate Next Level