Over the last few weeks I've made countless brews with different bloom amounts. It has proven to be quite interesting. Traditionally, we have been told to add double the amount of water compared to your dose, so 20g of coffee will equal 40mL bloom. With this in mind, and trying to get the best cup possible, I started playing with different bloom amounts starting from a ratio of 1:1 all the way to 1:5.
The coffee I used was a filter roast, Costa Rican Las Lajas (Black Honey Process), 23g of coffee, 300mL water and a brew time of 2:30 minutes. All the beans were ground on the Helor 101 hand grinder. The grinder was set to the 32nd point. The cups were tasted over a 15 minute period.
I was looking for the most balanced and flavoursome cup. The results showed big differences in taste and one ratio definitely stood above them all.
4 - Very bad
5 - Bad
6 - Ok
7 - Good
8 - Very good
9 - Excellent
In conclusion, the bloom dramatically changes the final cup and I felt that the 1:3 ratio gave the best result (my latest V60 recipe uses this bloom method). Feel free to give this a go and taste the difference yourself.