Repitch on S23 slurry?

[macleanb]

Hi Guys

Will be racking my 1051 pilsner off its slurry this coming weekend after 3 weeks PF. The ferment was 12c with 16c rest, then down to 4c for a week. Will my slurry be re-usable or should I start fresh.

And while were on the subject - do I actually put my new wort onto the old slurry in the original FV (YIPPPEEEE - I hate washing-up) or do I need to transfer to a knew FV?

Cheers & tfn benm

[boingy]

You defo need to start with a clean, sanitised FV.

Re-using the slurry is possible but carries a small risk of infection/mutation/failure/explosion. OK, I lied about the explosion bit. Pro-breweries use boffins (probably in white coats) to process the slurry, remove the trub and debris, acid wash it and then select the best cells to repitch in the next brew. This process is not entirely beyond the means of a homebrewer but is fiddly, time consuming and needs a certain amount of equipment.

For a yeast as cheap as S23 I'd say just buy a fresh packet. However, it might be an interesting exercise to make the next brew and ferment, say, a gallon of it in a demijohn with the slurry and the rest with new yeast. Then you can see if it makes any difference.

Alternatively, if you are feeling brave (or reckless), you could just scoop out a few spoonfuls of clean, trub-free slurry and make a new starter from that. Remember to sanitise everything.

And regardless of what you decide, definitely clean and sanitise the FV!

[edit1now]

I got the S-23 slurry from the primary of my Munich Dunkel and used it a week later for my Schwarzbier. It had spent the time in the beer fridge, in a small demijohn covered in clingfilm. I acid-washed the slurry and gave it a litre of sterilised wort to think about while the new beer was boiling. Worked pefectly well, and since this was for another lager it was great having the comparatively huge volume of yeast.

[Parva]

Boingy, I think you miss the point. If the beer that is coming out of the FV is fine and not infected then the FV is still sanitary. I know several people who have racked a beer off to a keg and immediately put wort into the same FV with no cleaning whatsoever and had perfectly good beers off it. Indeed it is something I plan to do myself at some point in the future.

[boingy]

Boingy, I think you miss the point. If the beer that is coming out of the FV is fine and not infected then the FV is still sanitary. I know several people who have racked a beer off to a keg and immediately put wort into the same FV with no cleaning whatsoever and had perfectly good beers off it. Indeed it is something I plan to do myself at some point in the future.

I don't think I have missed the point at all. Re-using an FV in this manner is a risk and brewing is all about reducing the risks. Just because people have got away with it does not mean it is a good thing to do. The FV is not as sanitised as it was when you started. It will have rogue yeast cells in it and it will also have a certain amount of bacteria. Fresh wort is much more vulnerable than beer that has completed its primary fermentation.

If you need any more convincing, ask yourself why pro-brewers clean down and sanitise the FV for every batch. We put a lot of effort into creating that wort. Why risk spoiling it for the sake of 10 minutes cleaning?

Maybe you get away with it, maybe you don't. It seems to me a risk not worth taking.

But, hey, it's your beer and your choice.

[Parva]

I was as sceptical as you when I first saw this done actually and I certainly wouldn't want to lose 5 or 10 gallons of beer but having seen it done I shall definitely have a go.

[Digby Swift]

Wouldn't that be massively over pitching?

[Invalid Stout]

There are risks and risks, aren't there?

Yes, you will have more nasty microorganisms in a FV that has been sitting about for two weeks. You also have a yeast culture which is very strong and abundant and ready to start fermenting almost immediately and will probably predominate.

It's really down to what you feel comfortable doing.

I've had mold in beer started in a clean FV, and I've had uninfected beer from a FV that had had another beer in it before without a wash.

[subsub]

I do it about once a month, especially if things are tight on the farm ie winter. No probs here (but be prepared for the krausen to climb out of the fv)

[sib67]

Boingy, I think you miss the point. If the beer that is coming out of the FV is fine and not infected then the FV is still sanitary. I know several people who have racked a beer off to a keg and immediately put wort into the same FV with no cleaning whatsoever and had perfectly good beers off it. Indeed it is something I plan to do myself at some point in the future.

I did this myself for several brews in a row without any problems - my reasoning was exactly as you've stated. I only stopped when I started using S04.

I have a couple of Wyeast smack packs in the fridge, and will probably do the same again if I can't be bothered faffing about. I realise that there are risks involved, and I may be massively over pitching, but it's worked ok for me in the past.

Edit - please note - I am not saying that I necessarily think this is good practice, just that there's probably a good chance of getting away with it if you're feeling lazy! I know many people will disagree. It would be interesting to hear if anyone has used this method and got an infection.