MWJB wrote:Doesn't this work just as much in our favour? The fines sinking quickly & settling together hopefully in such concentration as to stall their extraction, the boulders still floating/in low concentration liquor, thus able to carry on extracting until knocked down, or sinking of their own accord later in the brew?

This is why, of course, you'll grind to a particle size for your intended extraction timing and why you use a high quality burr grinder that won't create excessive fines.

Indeed, but all burr grinders typically produce a range of particle sizes at any setting, all make fines & boulders (without sieving), just in differing proportions.

Yes, there is imperfection all around us. Fines aren't a problem if you're using a quality grinder.

Not to be argumentative, but fines are a problem in any grinder. But even more specifically burr grinders versus large flats.

MWJB wrote:Doesn't this work just as much in our favour? The fines sinking quickly & settling together hopefully in such concentration as to stall their extraction, the boulders still floating/in low concentration liquor, thus able to carry on extracting until knocked down, or sinking of their own accord later in the brew?

You may be right here.

drgary wrote:Yes, there is imperfection all around us. Fines aren't a problem if you're using a quality grinder.

My EK-43 has a fines problem. So there.

I was just making a cup of coffee in my Aeropress this morning when I asked myself the same question as OP, Googled and found this thread. I thought that blooming had to do with releasing trapped CO²? So I wondered why that would be necessary, since the grounds are immersed for the extraction period, rather than having water forced through for a brief time by pressure or gravity... In my mind, if I'm using inverted method, the CO² has the same amount of time to escape if I bloom or if I don't bloom. Am I off base here?

After hundreds and hundreds of Aeropress coffee, I can say this: I've never made a cup without blooming that I felt was awful because I didn't bloom. I've also never felt like the cups without blooming were much better or worse. Since Aeropress is closer to immersion brewing than pour over, I'd say the choice is down to preference.

Probably also the act of stirring alleviates the need for a bloom.

I use a fine grind, just a bit above an espresso grind. Pour in my hot water, give it a 15 second or so stir with a coffee straw, top off the water and press for about 30 seconds. Works good for me. A good heavy stir breaks up the bloom and gets all the coffee in suspension.