from Hacker News

A scientific run-down of coffee blooming

by green-eclipse on 5/8/24, 9:08 PM with 56 comments

• by decafninja on 5/9/24, 12:08 AM

  I went through my coffee hipster phase. But I eventually came to the conclusion that my palate is just too unsophisticated to tell the difference between supposed “hints of blueberry and molasses” in third wave hipster coffee from a boutique roaster versus the cheap coffee that my local newsstand brews every morning.

  Now my only concession to coffee is brewing a cup on a Technivorm. Also Hawaiian coffee is super smooth and mellow which I like, but serious coffee aficionados apparently don’t like it for the same reason.

• by vundercind on 5/8/24, 10:58 PM

  I’ve long assumed that the main effect of the bloom is to soak the grounds so the rest of the water you pour in goes through slower, and all the other alleged effects were minor compared to that.

  But maybe the CO2 removal stuff really is a big deal.

• by 0xbadcafebee on 5/8/24, 10:50 PM

  In my own attempt to bloom coffee in an Aeropress, the result is, strangely, that it takes much longer to extract the coffee to 'full strength' if I bloom it, compared to not blooming it. If I bloom the coffee, then fill up with water and stir, the result is under-extracted unless I brew for longer. If I just fill up the water immediately and then stir, it takes much less long to brew to the same 'strength'. This is the opposite of what should be happening. But I am using light-to-medium roasted coffee, and this article notes that bloom and roast are interconnected, so perhaps this is normal? All I know is, coffee brewing seems to be much more an art than a science, regardless of how much you try to focus on the science. Dial it in to what tastes good to you, and that's all that matters.

• by soneca on 5/9/24, 1:09 AM

  I learned that I like without bloom phase. The CO2 getting in the way of extracting flavor might be a good thing, since (at least that is my understanding) the more acidity flavors are extracted later. I like the coffee with more sweetness and less acidity, so I just skip the bloom phase, pouring all at once, it extracts less of the coffee, only the good (for me) parts.

  Gentle circular pouring can prevent dry coffee blocks and the creation of channels. I also do a little swirl with the filter to flatten the coffee bed. So it is possible to avoid those issues even without the bloom phase.

  It works for me, even though I am not a hundred percent sure that I got the science of it right.

  At least, some coffee specialists support my choice:

  https://youtu.be/miuPSjazpyw?si=_UPZfh9O0YYZwmri

• by CoastalCoder on 5/9/24, 12:26 AM

  One coffee phenomenon I'm curious about: why does old coffee get cloudy?

  On the day I brew it, it's a dark brown translucent.

  But if I leave it in the pot overnight, it's definitely more opaque.

  My wife claims it tastes the same as the day before.

• by brrrrrm on 5/9/24, 1:02 AM

  It mentions immersion methods and then never revisits it :(

  I used to use a Chemex but found the whole process so fickle and involved. I've since switched to a Clever dripper (similar to the hario switch) and found that my coffee life has improved substantially. The basic idea is to let the coffee sit with the water for a bit and then flip a switch to drain it into your coffee. I prefer the consistency of the method and haven't noticed a difference in flavor.

  My latest project has been attempting to speed up the cold brew process (to get low acidity cold coffee for the summer) and I've taken to using a sous-vide. The idea is that low heat will reduce the time needed for extraction without actually causing the water to leech acidity from the beans. It's worked, but results were kinda meh. I just bought some PH strips to run a more thorough experiment, though.

• by charlie0 on 5/9/24, 1:35 AM

  I'm curious to how this applies to the Aeropress because in that system, you actively stir the coffee for several seconds.

• by elwell on 5/8/24, 11:14 PM

  > 30 grams of coffee, 500 grams water at 205°F

  Woah, that's too hot IMO, and a bit watered-down.

  Me: 33g coffee, 350g water at 190°F