Full Immersion...Wet Bloom vs Hot Bloom

I posted something about this on my Instagram a few weeks ago. Some people are using a cold bloom to initiate the brewing process in full immersion processes. So, I thought I'd put this process to the test and brew it side by side with the Aeropress. 

I'm going to be using two Aeropresses, using the exact same brewing recipe for both and a Guatemalan coffee from Padre Coffee. The only difference will be that one will have a 5 minute cold bloom.

Recipe/Process:

Cold Bloom Process

  • 18g coffee beans, ground to a medium coarseness.
  • Add 50mL cold water, stir and let sit for 5 minutes. 
  • Add 150mL 96 degree water and stir 3 times.
  • Wait 1 minute and press down slowly (approximately 45 seconds to 1 minute).

Total brew time should be approximately 7 minutes (5 minutes for the cold bloom and 2 minutes for the hot process).

Hot Bloom Process

  • 18g coffee beans, ground to a medium coarseness.
  • Add 50mL 96 degree water, stir and let bloom for 30 seconds.
  • Add 150mL 96 degree water and stir 3 times.
  • Wait 1 minute and press down.

Total brew time should be approximately 2 minutes.

The results are very interesting. I initially thought that the results wouldn't be too different but after tasting them side by side the differences in body, acidity and texture were substantial. The actual flavour notes didn't seem to differ that much. The cold bloom cup was much more balanced and heavier bodied. The other was sweeter, bright and a lot higher in acidity. I also think leaving the cold bloom in for longer would give you a better brew as well. It's definitely something to think about when brewing full immersion coffee. I would like to also add that I'm not trying to change the industry, I just find this stuff interesting. Let me know your thoughts if you give it a go.