Pitching onto sour yeast cake

cunnol · Apr 21, 2016

So I made a kettle sour berliner weisse, og 1032. Not sure of the ph as I judged that by taste and some ph strips. Let's say a little below 4. It's now ready to keg and I've got a wheat beer planned. Standard pils and wheat recipe. I have safale us 05 so can make an American wheat beer but ideally would want to use a more flavorful yeast. The sour yeast is safale k 97 so I'm thinking I'll rack onto that.

With the yeast cake being such a small percentage of the volume in the fermenter (5 gallons) do you think it will impart much noticeable sourness?

A little bit probably wouldn't hurt the flavour, if it's good enough for Guinness...

didinho · Apr 21, 2016

i guess to give sourness in 5 gallons you need more than a half liter yeast cake...

beergolf · Apr 21, 2016

Did you kettle sour and then boil the beer? That is common for a Berliner Weisse..

If you did there will be no souring bugs left. The boil kills the lacto.

cunnol · Apr 22, 2016

beergolf said:
Did you kettle sour and then boil the beer? That is common for a Berliner Weisse..

If you did there will be no souring bugs left. The boil kills the lacto.

Yeah, I was thinking more of the actual amount of lactic acid left in the yeast cake and small amount of beer that would be left. I'm sure that'd be so diluted you couldn't taste it and if so it wouldn't be a bad taste to have there

Aristotelian · Apr 26, 2016

Never done it, but I would guess it would be fine, similar to hop trub. If you are really concerned you could do a quick wash of the yeast. Boil a mason jar of water, let it cool, swirl with the yeast cake, let trub settle, then pour suspended yeast into a mason jar. You will further dilute the acid while also getting rid of trub. Probably unneccesary but couldn't hurt.

beergolf · Apr 26, 2016

cunnol said:
Yeah, I was thinking more of the actual amount of lactic acid left in the yeast cake and small amount of beer that would be left. I'm sure that'd be so diluted you couldn't taste it and if so it wouldn't be a bad taste to have there

The point I was making is that if you kettle soured and then boiled there will be no lacto left. The boil will kill all the lacto. Just because the beer is sour does not mean that the yeast cake will make your next brew sour.