What would you do with this yeast?

[Calder]

I've been brewing sours for a few years now and have a rhythm of making 2 to 3 a year. I bottle 8 or so gallons, and then make a similar each time. I made one in January, and will not have the available fermenters to make another until I next bottle some sours in May or June.

My problem: I bought a pack of Wyeast Roeselaire a couple of weeks ago as part of an on-line buy with some hops. The package arrived sometime last night. Fed-Ex had left it on my doorstep, and I discovered it when I left the house at 6:00 am this morning. The temperature was 3 F. I don't know how long it had been there, but the yeast pack was frozen. I put it in the fridge and about 12 hours later it seemed to have thawed. For reference, the mfg date was Jan 14.

It is going to be 4 months until I need to use this yeast (blend), what should I do with it in the meantime? I really would like to know what people think.

1) Dump it, and buy fresh. There is no-way of knowing what is still viable, and committing it to 8 gallons could be a waste of time and beer.

2) It should be fine. Keep it in the fridge, and use it when I brew in June. This what I had intended to do.

3) Make a starter (~1.030) about 2 quarts, and keep it with an airlock on and use that to pitch in the beer in June?

4) Make a starter (~1.050) about 2 quarts, and keep it with an airlock on and use that to pitch in the beer in June?

5) Make a small extract batch (2.5 gallons LME+Special B+low hops). When needed, move 2 gallons to small fermenters and use cake + remaining liquid as starter for new batch.

6) Use a different (or same) 'bug' blend, and just add this as an addition, to use any bugs that might still be viable.

I'm currently thinking about #5, to try and maximize the bugs for the main batch. Big concern is that all the 'bugs' survived. Not sure I'll know in 4 months time.

 

[dantheman13]

#5 seems like a low risk method to me. I guess the best choice if money and time aren't a factor is to throw it out. But if you want to make use of this stuff, #5 looks good to me! If it sucks, just toss it, and if it's good you have your yeast cake!

I think the biggest concern is that you don't have enough viable bugs to get a fermentation that is going to make you feel comfortable with pitching on that yeast cake. Maybe add some brewer's yeast to be sure you get a good fermentation, or wait a week and pitch more Sacch if you don't get a good fermentation by then?

 

[TANSTAAFB]

Frozen = dead. I'd be pissed and would be bitching out the local fed ex office, but nothing usable survived 3° and frozen solid. Sorry man. If you do anything make a small starter to minimize the $$ you put out. No sense throwing good money after bad...

 

[blizzard]

I agree 5 is low risk if you want to try it, but I would vote for 1 - toss it and get a fresh pack. Best case some of the strains survived but not all - you won't be pitching the whole roselare blend. Worst case - everything is dead. Either way, your beer could be lacking. Too much of a risk on a beer you spent so much time on. And for less than $10? My (one time) experience with roselare is that you won't know in four months what you have.

Option 6 is not be a bad one either - it won't hurt anything to add this pack to another. If you already have something going with a strong pitch of roselare you could inoculate your batch with that.

 

[cjw10]

Frozen = dead. I'd be pissed and would be bitching out the local fed ex office, but nothing usable survived 3° and frozen solid. Sorry man. If you do anything make a small starter to minimize the $$ you put out. No sense throwing good money after bad...

Really? Cause it seems a lot of people freeze yeast cultures in order to use them later. While the Roaselaire contains brett (which is shown to survive freezing), but lacto & pedio, which I'm not 100% on how well it survives freezing, but I'd lean towards both surviving it.

Is frozen yeast the best? Probably not, but it's not the worst thing in the world. It's better than boiled yeast. There is a reason that we heat meat after it's frozen. And there's a reason we don't freeze our wort to kill the bugs.

I'd do a starter and a small batch and see how it turns out. Best case, you made good beer. Worst case, you wasted $10-15 on supplies and learned a lesson. So #5 for me.

I could be completely wrong, just my $.02

 

[TNGabe]

Get some fresh when you need it. The siver lining is you'll have a freshly packaged culture when you need it instead of stuff that's been slowly dying in your fridge for 4 months.

 

[TANSTAAFB]

Really? Cause it seems a lot of people freeze yeast cultures in order to use them later. While the Roaselaire contains brett (which is shown to survive freezing), but lacto & pedio, which I'm not 100% on how well it survives freezing, but I'd lean towards both surviving it.

Is frozen yeast the best? Probably not, but it's not the worst thing in the world. It's better than boiled yeast. There is a reason that we heat meat after it's frozen. And there's a reason we don't freeze our wort to kill the bugs.

I'd do a starter and a small batch and see how it turns out. Best case, you made good beer. Worst case, you wasted $10-15 on supplies and learned a lesson. So #5 for me.

I could be completely wrong, just my $.02

When people prepare a culture to freeze it they are using a glycerin/ glycerol solution so the yeast cell walls don't rupture. Water turns to ice crystals and expands and the yeastie beasties die a violent death! A quick Google search does suggest that freezing does NOT kill most bacteria however, it may just put them in a dormant state.

I would still be concerned about ratios though. While the bugs may have survived, the variety of yeast strains likely did not, or are so greatly reduced that they will be out of balance.

 

[40watt]

The yeast should all be dead. The bacteria dormant.

I would throw it in with another project. The same way people toss dregs from a bottle in with an already sour fermentation. At least you know that won't hurt anything. Maybe combine with a viable smack pack. Those yeast are ruptured and might pose a greater risk of autopsies off flavors if they aren't consumed or racked off of.

 

[ColoHox]

Freezing does not equal dead, although there will be reduced viability. The problem with trying to make a starter from the remaining cells is the proportions of the various components will no longer be accurate, as was mentioned by TANSTAAFB.

The roselare blend contains ale yeast, Brettanomyces, and lactic acid bacteria in a particular ratio. Making a starter or a small batch from what you have will not produce a beer consistent with previous batches using this blend. I agree with blizzard, if you are going for consistency and flavor complexity, buy a new tube. If you want to ferment wort with a microbe, pitch away.

 

[40watt]

Ice crystals are jagged and sharp. They puncture yeast cells. The vast majority of those cells are not only dead, but burst open.

 

[ColoHox]

Ice crystals are jagged and sharp. They puncture yeast cells. The vast majority of those cells are not only dead, but burst open.

The crazy thing is, there was probably around 30 billion cells in that tube to begin with. If 90% of those cells die, that leaves 3 billion cells. If 99% of them die, that leaves 300 million cells. This same concept applies to the use of hand-sanitizer.

While that is not enough cells to ferment a batch of beer, that is plenty of cells left to grow up if needed.

 

[40watt]

Yeah. I wouldn't be afraid to make a starter just for experimentation sake.