Maybe you’ve just brewed something a bit exciting – which involved splashing out on some liquid yeast – and now you’re thinking that you’d quite fancy using that same yeast again, but without having to fork out more cash to White Labs or Wyeast…
Well you’re in luck. Here’s the Yeastismybitch guide to re-using your yeast:
Once your beer has finished fermenting and you’ve racked it out of the fermenter into kegs or bottles; pour a litre or so of boiled (and then cooled to tepid) water straight on top of the remaining yeast.
Give the whole thing a good swirl until you’ve got a creamy looking soup.
If your fermenter is a glass carboy, let it stand for about twenty minutes, if you’re using a plastic bucket you’ll have to pour the lot into a sterilized glass demijohn or whatever and let it sit there.
In time the creamy-looking soup will start to separate – and once you notice a clear line of separation between the two different types of soup, pour the top lighter layer off into another smaller sterilized clear glass jar or container.
You can now discard the remaining heavier soupy sludge that was left behind and wash your fermenter – that stuff was just the trub (pronounced “troob” – if our US cousins are to be believed) and trub consists of dead yeast, coagulated proteins, conspiracy theories, shadows and lies and all that sort of stuff.
Keep an eye on the smaller glass jar and watch for another line of separation (which may take longer, this time) when you see that separation clearly – pour off the top caramelly/watery layer into another sterilized container, stick a lid on it and bung it into the fridge – this should be the healthy yeast that’s left in suspension, the remaining trub in the original container can also be discarded.
After a while you’ll notice a nice solid layer of dormant yeast cells forms at the bottom of the jar – and there’ll be some clearish liquid sat on top (see main picture)
There you are…you’ve just washed some yeast and it should keep for a good couple of months in the fridge.
When you want to use your washed yeast, pour off the watery layer, leaving a little bit to swirl up the solid yeast layer from the bottom of the jar. This liquid yeast can now be used to make a starter.
I’ve just washed some Belle Saison yeast dregs from my two saisons – so I’ll let you know how that yeast turns out…
Keep an eye out for an article on making yeast starters…it should be appearing above this fairly soon…