Wondering, how lucky do I feel? ... yeast cake/fermentor wise.

[Dland]

So I'm considering brewing today even though in a bit of a gale, (at least it is warmish out) but here is my question:

I racked out of a stainless conical last Tuesday, had been normal ABV lager with S-189, normal controlled fermentation at 54F. Conical has been sealed with blow tube in sanitizer, heat off fermentor in a 46F cellar.

How many of you would haul the fermentor up the stairs, clean, re sanitize and pitch fresh, vs pump the new (properly cooled) wort back down to fermentor? I have done this before with no problems, but I think the longest I waited in past was 3 days.

 

[IslandLizard]

You mean pitching onto the old yeast cake left in the conical?
How long has it been in there, since you packaged the beer? Much longer than 3 days I gather.
Unless you did a closed transfer, that conical is filled with air. And you can't really resanitize it.

You'd be grossly overpitching. Using 1/5-1/4 of the cake (or a 1/3 since it's a Lager), should be plenty.

It's a toss up. I've left yeast cakes in (covered) buckets for a week and never felt comfortable pitching on top of that or reusing that cake. If it were fresher, 1-3 days, sure, I'd use the cake but in a cleaned and sanitized fermenter.

 

[Dland]

Yes, to old yeast in sealed conical. It has been 5 days, transfer to kegs was closed pushed out w CO2.

Bottom of conical holds about a liter, most of solids were dumped during trub dump before beer was racked to kegs. In the past when I have done this it has not seemed overpitched.

The main point in this for me is when I can skip the fermentor cleaning, it saves considerable effort.

 

[IslandLizard]

A sealed fermenter filled with CO2 keeps a lot better than if it were air. I'd say it's fairly safe to use without cleaning/sanitizing.

I'd go for it, just as you did in the past!

 

[Dland]

I think it's going to be fine. I opened another fermentor that had been sitting sealed and empty a day longer, and had two batches since last cleaning, and it looks like it would have been OK. The fermentor for today has only had one batch since cleaning.

But I will post back if this turned out to be a mistake.

 

[foolsbrew]

I think this is one of these things we are unreasonably cautious about since most people think of the yeast cake as the most important part.
If anything, there is a lot more chance of something going wrong in a yeast-wort mix than the yeast cake alone, and people open ferment just fine. The yeast is already the dominant culture in the cake.

There is far less room for things to go wrong compared to a wort. It's reasonably safe. People also do no-chill in sealed containers, which I think is riskier than a sealed yeast cake and they safely let it sit for a few days.

Of course you already know this and probably just posting for peace of mind, so I am going to say go for it Best of luck.

You'd be grossly overpitching. Using 1/5-1/4 of the cake (or a 1/3 since it's a Lager), should be plenty.

I agree a smaller portion is enough, but the whole cake is just fine isn't it?
I'd throw away 2/3 just to keep recirculating the yeast and avoid having too much yeast since I usually pitch to yeast until I switch to a different strain.
A yeast cake with trub is roughly 1/10th the volume of the final beer, that's plenty, but not too much so far as to cause problems, IMHO.

 

[Dland]

Well..., the "happy little vegemites" are already working.

 

[Dland]

Update on this post:

It has now become a regular practice to brew two or three batches of beer without unsealing conical, sanitizing and re pitching. I have only done this when I will be brewing another batch within a week of emptying fermentor, if I'm not going to brew for over a week, I'll clean it out and start fresh. Three batches is as far as I have pushed this, and don't plan to go further.

Notes; All transfers and trub dumps are displaced by CO2, not air, and fermentor is well sanitized at the start. I have used Fermentis dry pitched yeasts, no possibility of contaminated starter. On the first pitch with new yeast I do not oxygenate, but I do with subsequent batches. Do at least two trub dumps per fermentation when re using yeast cake in fermentor, one at beginning and at least one near end, besides sampling and cold break removal, it is good not to let the solids accumulate. Fermentor with yeast cake is kept at fermentation temp between batches, with blow off tube in sanitizer attached.