The bloom phase, or blooming the coffee, refers to a technique that uses a small amount of water to initiate the brew and resting it before adding more water. Usually the amount used is 2 to 3 times the dose of coffee in grams.
The main goal of blooming is to quickly degass the coffee. The CO2 generated during the roasting process will otherwise generate bubbles, which insulates the coffee particles (decreasing extraction yield) and contributes to channeling (decreasing uniformity of extraction).
The blooming phase doesn't need to target high extraction because CO2 is very volatile. Some professionals argue this to be an opportunity for a cooler bloom (around 60~70 Β°C) to try and preserve aroma. Most people don't bother. Chasing volatile aromatic compounds hasn't yet been shown demonstrably fruitful.
An alternatives to swirling: using a spoon to stir the coffee bed; Wet-WDT (or WWDT for short).
The process of dialing in a coffee refers to the process of refining the recipe for a given coffee sample, usually a newly opened package.
The most straightforward approach is to pick a simple recipe and stick with it. Simpler recipes are easier to reproduce and consistency is essential for fine adjustments. Start with reasonable defaults: water at 95 C; 60 g/L dose; 60 s bloom; a grind setting that puts the whole brew between 1m30s and 2m30s. The grind setting is highly dependant on the grinder characteristics, just pick whatever seems to work often enough.
Either start brewing with the defined defaults, or try and guess a few initial adjustments based on roast level and coffee varietal. For darker roasts or denser beans, one would generally want to lower extraction; the opposite for very light roasts or stale beans.
Burnt notes? Extract less. Hollow profile? Extract more. To increase or decrease extraction, play with temperature, dose and contact time: Β± 5 C, Β± 5 g/L, Β± 20 s. One way to influence contact time would be to change the grind settings, but try using agitation first.
The last resort is changing the grind setting. Most coffees are plausibly extracted close to their optimal within the parameter variations of temperature, dose and agitation alone. Take this opportunity to eliminate one variable (grind size).
There's no significant benefit to shortening bloom time except expediency so it's fine to just stick to the default. Very fresh and gassy coffees might benefit from a longer bloom, maybe up to 2 minutes, the bubbly-ness will tell.
Total brew time should be in or about 1:30 to 2:30.
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).
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.
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.
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