How do you aerate?

[Dr_Jeff]

Inline aeration with a diffusion stone attached to an oxygen tank.

^^ This at usually 1 liter per minute, sometimes more. ^^

 

[Deadalus]

^^ This at usually 1 liter per minute, sometimes more. ^^

I've since switched to a wand and I also just built a TC diffusion stone setup for my unitanks. I switched from a plate chiller to a cfc, and could have kept the inline setup but the stone had cracked without my knowing as it was cip'ed. Just got it setup, will be using it on my next brews.

 

[user 246304]

5 gallons, ss wand with diffusion stone. I just goose it then draw back a bit for 50-60 seconds. I go by the sound in terms of flow rate. In a 7.9 g bucket basically I stop when the foam is about to crest the top anyway. Top cropping 1469 or British Cullercoats always takes off like crazy and finishes out well in normal (usually, 48 hour) period, before slow ramp down to 50F.

 

[tdf]

If I'm pitching dry yeast, I don't aerate.
If I'm pitching a fresh starter I will pitch it right off the stir plate since the yeast is active and has plenty of oxygen.
If I'm re-pitching without a starter I will pull out the wand + tank.

 

[VikeMan]

If I'm pitching dry yeast, I don't aerate.
If I'm pitching a fresh starter I will pitch it right off the stir plate since the yeast is active and has plenty of oxygen.
If I'm re-pitching without a starter I will pull out the wand + tank.

The yeast coming off the stir plate have been using the oxygen they picked up to build sterols and fatty acids, and using those sterols/acids to build cell walls for the cell divisions that they were doing in the flask. (They don't actually store oxygen per se.) They won't have built/stored much "extra" sterols (unlike the condition of dry yeast). But they'll still need to do more divisions in the beer wort, and oxygen could still be a limiting factor there.

TLDR: I recommend oxygenating wort that will be fermented with non-dry yeast, regardless of its "freshness" or starter type.

 

[1OldJarhead]

What do you to aerate your wort prior to pitching? Use oxygen? Shake the fermenter? Stir it fast/hard for a while? Something else?

 

[1OldJarhead]

I wondered about that, too. Historically I shook the hell out of the carboy several times to turn it into foam, not knowing that it’s not all the damn bubbles you create, but the oxygen in that small 1-gallon headspace that you’re trying to dissolve. Still, that was enough, barely. Online there’s a guy who’s had success dumping the wort from one five gallon bucket into another and back again a few times. Unless you’re The Rock there’s going to be some spillage, and exposure to ambient air with its tiny dust and bacteria microbes. But he said it was an improvement in brew quality because now the yeast had all that oxygen food booster. But if you look at enough YouTube advice clips you’ll see how amazingly easy the Ace Hardware (or other) oxygen bottle into a diffuser stone (bought online cheap) works. Sixty seconds in the cooled wort in your carboy, bing/bang/boom.

 

[tdf]

The yeast coming off the stir plate have been using the oxygen they picked up to build sterols and fatty acids, and using those sterols/acids to build cell walls for the cell divisions that they were doing in the flask. (They don't actually store oxygen per se.) They won't have built/stored much "extra" sterols (unlike the condition of dry yeast). But they'll still need to do more divisions in the beer wort, and oxygen could still be a limiting factor there.

TLDR: I recommend oxygenating wort that will be fermented with non-dry yeast, regardless of its "freshness" or starter type.

Experimentally, pitching a 2-4L starter that's right off the stir plate (something like 10-15 ppm oxygen) into a split batch and then adding pure o2 to half didn't have any effect on either the speed at which fermentation took off or the final gravity.

 

[VikeMan]

Experimentally, pitching a 2-4L starter that's right off the stir plate (something like 10-15 ppm oxygen) into a split batch and then adding pure o2 to half didn't have any effect on either the speed at which fermentation took off or the final gravity.

I'm not really surprised by either of those observations. But it doesn't refute what I said (if that was your intent).

But I'd be interested in reading the paper. Do you have a link?

 

[wepeeler]

Like others have said, no O2 for dry yeast, 60 seconds with wand and diffusion stone + O2 tank for liquid.