How late can/should you aerate a huge beer?

[blizzard]

I'm seen a few threads and recipes for huge beers where a brewer will aerate once or twice a day for the first few days of fermentation. Sometimes this aeration occurs during a sugar addition. So, how late into fermentation can you aerate without worrying about oxidation? What is the ideal aeration schedule for a monster-sized beer? And do you need to make a sugar addition if you plan to aerate after pitching?

 

[Walker]

No expert...

But my understanding is that once the yeast starts to actively ferment, it has finished propagating and O2 is no longer needed or desired.

So, if it is fermenting and you shake it, you are adding air that served no useful purpose.

 

[david_42]

Right, making the yeast switch from fermentation to growth and back repeatedly isn't a great idea. I aerate for 15 minutes every 6 hours for the first 48 hours, then stop. Mostly, though, I go with a yeast cake for big beers.

 

[archiefl98]

So, if it is fermenting and you shake it, you are adding air that served no useful purpose.

If it's fermenting and you shake it, wouldn't you actually just be taking CO2 out of solution? Since the fermenter would be purged of O2 at that point anyway, wouldn't it really just be swirling up any yeast that already fell out of suspension?

This is a question, not a statement. I'm just wondering if after active fermentation starts, is there any actual oxidation issues from swirling. (I'm not the most careful person when I move my fermenters)

 

[Walker]

If it's fermenting and you shake it, wouldn't you actually just be taking CO2 out of solution? Since the fermenter would be purged of O2 at that point anyway, wouldn't it really just be swirling up any yeast that already fell out of suspension?

This is a question, not a statement. I'm just wondering if after active fermentation starts, is there any actual oxidation issues from swirling. (I'm not the most careful person when I move my fermenters)

excellent point. shaking a fermenter that has actively fermenting beer in it just knocks around CO2. No aeration happens.

 

[archiefl98]

Thanks, that alleviates some concern for me.

 

[Beerrific]

It is my understanding that oxygenating a big beer 24-36 hours after pitching (even with signs of active fermentation) is a good step. I have heard a few commercial brewers say they do this, but I have not direct quote or reference. It would be something to play around with as it might change the character of the yeast.

 

[blizzard]

David42 - I'm definitely planning on a big starter. Would you aerate for 48 hours even if the krausen is up?

Archiefl98 - good point. I aerate via shaking, so I would have to rethink that.

 

[Delaney]

excellent point. shaking a fermenter that has actively fermenting beer in it just knocks around CO2. No aeration happens.

excellent. I was carrying a lager that had just begun fermenting down to my wine cellar. I slipped a the top of the stairs, while holding onto the carboy, and toboganed down the stairs on my back. Which is rather sore now. It's a miracle the carboy didnt break and slice my belly open.