Aeration

[beerisyummy]

Better to aerate wort in the fermentor before or after pitching yeast? Go.

 

[MoonBrewer]

Better to aerate wort in the fermentor before or after pitching yeast? Go.

I aerate immediately before pitching, mostly because I don't want yeast getting in the diffusion stone and finding its way to future batches. I do sanitize the wand and stone before use but why take chances?

 

[Chorgey]

I always aerate just before pitching, never had a problem.

 

[day_trippr]

I pitch first and O2 immediately...

Cheers!

 

[radwizard]

Pitch then 02 for me

 

[stosh]

I put the aeration wand and tubing in a wallpaper tray to sanitize, then aerate, then pitch.

I crack the air open a little before putting into the wort and leave it cracked when I take it out and put it back into the wallpaper tray then turn it off. That way I reduce the chances of anything getting into the stone. Haven't had any problems (yet).

 

[DurtyChemist]

Aeration before pitching. I’ve done it this way since brewing extract years ago. Instructions said to and I knew I wouldn’t break yeast cell walls this way.

 

[Dland]

I pitch after oxygenating. I tried it the other way and the yeast does not seem to get going as quickly. I dry pitch as per Fermentis instructions. Perhaps the yeast prefers to hydrate more slowly.

While on the subject, how long do other people aerate/oxygenate for? I've been putting O2 though wand/stone at bottom of conicle for 4-5 minutes at 1.5/liters per minute. Judging from the yeast activity, this is enough, but sometimes I wonder if I am overdoing it or wasting 02.

 

[homebrewer_99]

I aerate my wort by racking it through a nylon net on it's way to the primary. No stirring needed. Then I pitch the yeast.

 

[day_trippr]

[...]While on the subject, how long do other people aerate/oxygenate for? I've been putting O2 though wand/stone at bottom of conicle for 4-5 minutes at 1.5/liters per minute.[...]

How big a conical? I run 0.5 lpm for 4 minutes for five gallons in the fermentor, which is half the rate but twice the duration as Chris White recommended in Yeast...

Cheers!

 

[Dland]

My conicals are 12.5 gallons, there is usually 10.5-11 gallons wort in them at start of fermentation. If I recall, 1.5 lpm was what it took to push 02 though the aerator wand, but it might work at slightly lower pressure.

 

[Frogger42]

Is touching the stone an urban legend? If I briefly played with it, I’d it ruined? Do I boil it? How would I know it’s ruined?

 

[couchsending]

My conicals are 12.5 gallons, there is usually 10.5-11 gallons wort in them at start of fermentation. If I recall, 1.5 lpm was what it took to push 02 though the aerator wand, but it might work at slightly lower pressure.

.25 lpm is all it takes

I believe the lowdo guys recommend .25 for 4 minutes for 5.5 g lagers. They’re using a dissolved O2 meter to verify...

This is one of those variables I’d love to be able to confirm but don’t feel like shelling out for the DO meter.

 

[couchsending]

Is touching the stone an urban legend? If I briefly played with it, I’d it ruined? Do I boil it? How would I know it’s ruined?

The oils from your fingers will get in there and clog the tiny holes in the stone and I believe once clogged it’s had to get them unclogged?? Run some o2 through it in a glass of h2o and see what it looks like..

 

[govner1]

Better to aerate wort in the fermentor before or after pitching yeast? Go.

I was taught to aerate (oxygenate) after pitching and that's what I've always done. I believe Papzian recommends that as well.
As far as issues w/ my stone I always flush it with O2 in a bucket of StarSan then dry.

 

[Frogger42]

The oils from your fingers will get in there and clog the tiny holes in the stone and I believe once clogged it’s had to get them unclogged?? Run some o2 through it in a glass of h2o and see what it looks like..

Lots of bubbles! okay, now how does anyone know how much flow there is on their regulators?

 

[day_trippr]

Yo! [raises hand]

Cheers!

 

[govner1]

Lots of bubbles! okay, now how does anyone know how much flow there is on their regulators?

I have an E tank of medical O2 with an adjustable flow rate & indicator on the regulator.

 

[couchsending]

I think morebeer sells a kit with a wand and an in-line flow meter.

 

[flars]

I was taught to aerate (oxygenate) after pitching and that's what I've always done. I believe Papzian recommends that as well.
As far as issues w/ my stone I always flush it with O2 in a bucket of StarSan then dry.

This may have been recommended when dry yeast was commonly pitched. The dry yeast would sit on top of the foam created by the aeration. Happened to me the first time I used dry yeast. Poured through the mouth of the carboy. Half hour later saw this pile of rehydrating yeast on top of the foam. Swirled the carboy to get it to drop.

 

[govner1]

This may have been recommended when dry yeast was commonly pitched. The dry yeast would sit on top of the foam created by the aeration. Happened to me the first time I used dry yeast. Poured through the mouth of the carboy. Half hour later saw this pile of rehydrating yeast on top of the foam. Swirled the carboy to get it to drop.

Really no need to oxygenate rehydrated dry yeast.

 

[Northern_Brewer]

Better to aerate wort in the fermentor before or after pitching yeast? Go.

It depends. If you're pitching into wort then you're above the Crabtree threshold, so you're only wanting oxygen to make fatty acids. You need to make fatty acids to enable cell division beyond what the yeast can do with its starting package of fatty acids; typically you need 3-4 rounds of cell division when brewing.

Dry yeast start with ~5% fatty acids, which is good for ~3 divisions so as mentioned above it's far less critical to oxygenate with dry yeast. You really need to oxygenate when repitching otherwise you'll end up stressing your yeast badly as repitched yeast have few fatty acids; along with blend drift it's perhaps the main reason that repitching doesn't work out.

The ideal time is 14 hours in, just as the yeast are really starting to suffer for lack of oxygen and use it most efficiently. But in the real world, just oxygenate before pitching, it will be fine.

 

[NitrogenWidget]

I’m only brewing 5 gal biab on my deck now so after the wort chiller does it’s thing I just dump the 5.5 ish gallons into the bucket as fast as I can without spilling. The I swirl the hell out of the plastic jug my starter is in and dump that none too gently. Cap the bucket and carry it down to my ferment chamber.
Seems to aerate just fine since haven’t had too many issues with fermentation.