Reusing yeast

[razzrockbolt]

Is it feasible to reuse part of the sediment from the primary fermentation to pitch a second batch or more?

[Doingatun]

Only recently on the forum we've had someone loose a batch due to reusing dried yeast. IMO it's not worth it for the sake of a quid.

Who was that Daab

Daabs comments seconded...With tears in me eye's I poured a fully matured cornie and 5 litre bottles of lovely looking foul tasting Bellhaven 80/- down the drain and out to sea.

Although I've got away with reusing dried yeast successfully a few times I Won't be doing it again.

[steve_flack]

Yes but if you are using dried yeasts it's not worth the risk as they ... aren't as clean/pure as liquid yeasts.

Whilst this is true, they are still apparently very clean in the packet - Fermentis claims <5 bacteria/ml when the yeast is pitched at the correct level. This might sound a lot but at that level there should be 6,000,000 viable yeast cells/ml. So there's about one bug per million yeasties.

In some ways, I think the purity advantage of liquid yeasts is overstated. Unless you're superclean then your liquid yeast starter probably has more bugs in it than a packet of dried yeast.

In both cases I think the problem comes post-packet. We don't brew in laboratory clean rooms - we brew in houses.

I agree with the bottom line though - dried yeast is cheap as chips and it isn't worth the risk to reuse it.

[razzrockbolt]

Ouch i hear you - yeah I guess one failed batch would cure you of a false economy.

[Rookie]

In the past I've gotten several uses out of a White Labs tube by only using half or a third of the tube and building it up a couple of times in a starter.
I don't do it very often as I don't brew the same type of beer batch after batch. I may brew a best bitter this time than do a wheat beer next than a steam beer.