Coffee Bloom Calculator
Enter your coffee dose, pick your brewer, and tell us how fresh the beans are. We show how much water to bloom with, for how long, and how much to pour afterwards.
Starting points for a normal-age coffee. Adjust to taste: fresher beans bloom longer.
How much water should I use to bloom coffee?
Use about 2 to 3 times the weight of your coffee grounds. For 20 g of coffee that is 40 to 60 g of water. Pour it evenly so every ground is wet, then wait before the main pour.
How long should coffee bloom?
Most pour over brews bloom for 30 to 45 seconds. Very fresh coffee, especially light roasts, benefits from the longer end or a little extra, because it holds more CO2. Older coffee needs less.
Why does coffee bloom?
Roasting traps CO2 inside the bean. When hot water hits the grounds the gas escapes and the bed puffs up. Letting that gas out first gives the water even contact with the coffee in the main pour, for a more even extraction.
Do I need to bloom stale coffee?
Stale coffee barely blooms because most of its gas is gone. A short 20 to 30 second wet-down still helps saturate the bed evenly, but it will not puff up much.
Should I stir or swirl during the bloom?
A gentle swirl or a quick stir helps wet every ground, especially with a flat-bed brewer like the Kalita Wave or in an immersion brew. Do not agitate hard. Our catalog lists 290 light roasts, the style that tends to bloom the most.