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Aerating slurry?

Seems as if I read you don’t need to aerate your freshly boiled and cooled wort, when you are going to pitch it with just-harvested slurry from a previous batch.

Is this true, and if not, is there even a bit of truth to the idea?

This is false. Slurry is no different than other liquid yeast, except it may have trub particles (which certainly are no substitute for oxygen).

You may be thinking of dry yeast, which doesn’t require (but is not harmed by) aeration, per the manufacturers.

See Danstar’s FAQ
for a yeast manufacturer saying essentially the same.

Thanks, Kiss. I was thinkin I read somewhere that second+ generation slurry had been thru a lag and growth phase so it didn’t need oxegon added to wort. Thanks again.

I suppose if you’re pitching enough cells that they aren’t going to need to multiply much before taking off then you probably wouldn’t need to aerate. I’d do it anyway though, there doesn’t seem to be a down side.

Yeast make byproducts that we want in the beer when they replicate, so you want some growth. Pitching a proper amount of yeast with aeration/oxygenation and encouraging healthy reproduction is preferable to over-pitching. I brewed yesterday and while the wort was cooling down to 62F I kegged the beer sitting on top of the yeast that I wanted to use in the new beers, oxygenated as usual, pitched a third of the cakes into each fermenter at 12:30 this morning and by 9:00 had slow but steady bubbles in the airlocks.

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