I've done yeast starters and I've re-used yeast beds but I have never previously harvested or captured yeast from a commercial beer. I tried it last night, inventing my process as I went but I'm wondering if anyone has a step-by-step based on my extensive experience.

So, how do you harvest yeast from a commercial beer?

1 Answer 1


First, make sure there's yeat there to capture! Some people mistake any sediment for yeast. For instance, every German lager I know of is filtered so there won't be any yeast. Assuming there is yeast, make up about 2 cups of 1.020 wort. Flame the opening of the bottle with the yeast you want to capture and pour the sediment into your starter wort. Let it ferment out. You probably won't see much activity at this point. Then you can use 1.035 wort to step it up to the amount you need. Depending on the OG and amount you want to pitch it into it may take a couple steps. And keep in mind that the lower the OG of the beer you want to capture yeast from, the more likely the yeast is to be in good shape.

  • In addition to making sure there's yeast to capture, also realise that some beers are filtered prior to bottle conditioning and primed with a different yeast (eg, a more flocculant yeast), so make sure you know exactly which yeast you're harvesting!
    – tallie
    Commented Oct 11, 2012 at 3:21
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    does anyone know if Rogue re-yeasts with something other than Pacman, or if their 22oz beers are bottle conditioned, or simply unfiltered? Need to get me some of that!
    – Pietro
    Commented Oct 11, 2012 at 13:30
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    I know for a fact that they don't. Most breweries use the fermentation strain because the have so much of it that it doesn't make economic sense for them to use something else. A few Rogue beers are filtered, but most are not.
    – Denny Conn
    Commented Oct 11, 2012 at 15:28
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    If you know someone who's into microbiology, they could culture the yeast strain. Provided there is any yeast to culture. Only a tiny amount of yeast (smaller then a water droplet) is needed.
    – David PGB
    Commented Oct 12, 2012 at 1:01

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