Freezing an alternative to pasteurization?

[nobeerinheaven]

I bottled a sweet caramel apple cider on Friday, and four days later I cracked one open to check the carbonation and I got a gusher. I had intended to use the stovetop method to kill the yeast, but now that's not an option. It would be a real pain to uncap and rebottle all of these, and it seems unnecessary.

Would solid freezing each bottle kill the yeast instead?

 

[Yooper]

I bottled a sweet caramel apple cider on Friday, and four days later I cracked one open to check the carbonation and I got a gusher. I had intended to use the stovetop method to kill the yeast, but now that's not an option. It would be a real pain to uncap and rebottle all of these, and it seems unnecessary.

Would solid freezing each bottle kill the yeast instead?

Freezing solid might or might not kill all the yeast, but you won't know because it WILL break the bottles!

 

[mrphillips]

True, your bottles will blow up if you freeze them...but even if you didn't, the yeast would probably just go dormant, and start chomping down on sugar as soon as they got back up to 50 degrees or so. They're a resilient bunch of critters!

 

[nobeerinheaven]

Hmm, I suppose it depends on just how frozen I let them get. Right now the bottles are intact but the first batch of 15 or so are solid frozen. But this wont kill the yeast? Will it kill enough of them to avoid bottle bombs after they rethaw?

Alternatively, are there other options besides the stovetop method for killing yeast?

 

[mrphillips]

You could use UV light to pasteurize, but I'm not sure of the process or how complicated it would be.

 

[nobeerinheaven]

I've seen enough posts regarding people who accidentally freeze their lagers (that they will have to re-pitch) for me to feel comfortable in experimenting. If it is sufficient, then this may be a good alternative to the stove top method.

 

[Genacide]

I've been stove top pasteurizing for some time now with great success. I've also missed the window and ended up with gushers and in the end I opened them all up and rebottled. Even if you do freeze them and stop the fermentation where it is now you still have gushers. My money is on the yeast coming active after you thaw the bottles and ending up with bottle bombs.

 

[TexasWine]

I've seen enough posts regarding people who accidentally freeze their lagers (that they will have to re-pitch) for me to feel comfortable in experimenting. If it is sufficient, then this may be a good alternative to the stove top method.

I don't brew beer, but I would venture that the reason they repitch is so they don't have to wait for the cider to work its way back to the previous levels of activity. Repitching allows them to essentially start back up where they left off, which results in drinking beer sooner

Ultimately the yeast will become active again, and my money is on getting bottle bombs as well. That is unless you refrigerate every single bottle.

I would uncap, recap, and pasteurize. The other option you have is to leave your bottles as is and pasteurize using your dishwasher. That way if one does blow you've got it contained.

 

[Randzor]

Also won't freezing push the carbonation out of the liquid?

 

[TexasWine]

Also won't freezing push the carbonation out of the liquid?

Typically the colder a liquid the more soluble gases are in them. As far as I know, a phase change from liquid to solid will not have an impact.

 

[Randzor]

Well here is an example: I live in Minnesota. Here in the winter, if you leave 20 oz pops and they freeze, if you unfreeze them they will be flat.

 

[TexasWine]

Well here is an example: I live in Minnesota. Here in the winter, if you leave 20 oz pops and they freeze, if you unfreeze them they will be flat.

By Jove! You're right! I just read that the water freezing effectively squeezes the CO2 forcing it all to the vapour phase. Then when you open the soda it all escapes without causing a big bubbly ruckus because it isn't in solution.

The exact same thing should happen to s cider or beer. Flat after thawing!

 

[nobeerinheaven]

I've also accidentally frozen enough beers to know that it wont make them flat. Moreover, the c02 pressure is still in the bottle, which means that if they became flat from freezing, they would recarbonate in the coming days.

As far as gushers are concerned, I think that gushing can sometimes be the effect of a high level of c02 trapped in the empty space of the bottle, not yet dispersed into the liquid. I remember watching a video of someone opening up beer being bottle conditioned every day for 3 weeks, and at one point the beer gushed, even though the same batch later on did not gush. Consequently, I think gushing may be a temporary phenomena. As long as no new c02 gets added in, and enough time is given for the c02 to assimilate into the cider, gushing may eventually just become a high level of carbonation.

So far, I've had success. I've not noticed any bottle bombs, and I'm one week out from bottling. I froze them on Monday/Tuesday of last week. One of the tubs I have the ciders in smelled faintly of apples, so it may be that at least one cap leaked a bit from the pressure.

By the way, this post suggests that freezing in liquid does effectively kill most yeast. The question is whether bottle freezing (which is less than a total freeze because a total freeze would break the bottle) is sufficient a freeze to kill off all the yeast. I'll post results, if it does work.

 

[ColoHox]

Aside from exploding bottles, freezing will just make the yeast dormant. Yeast libraries are stored in a freezer.

 

[Yooper]

Well here is an example: I live in Minnesota. Here in the winter, if you leave 20 oz pops and they freeze, if you unfreeze them they will be flat.

Haha- that reminds me of a friend's experience with frozen pop in Minnesota!

His brother came to visit, a "southerner" from Illinois, and he brought all kinds of stuff with him for his kids. He left a case of pop in the van.

The next morning, he had freeze-dried pop on the ceiling of the van! It was cold, and the pop not only froze, but the cans exploded and since it's a dry climate in the winter, the pop on the ceiling wasn't even wet- it seriously was "freeze dried". It must have sprayed out and instantly froze. Pretty cool, but a mess when he had to clean it up and the van warmed!

Anyway, glass bottles (and cans) will explode if something freezes solid in them. Fun stuff!

 

[nobeerinheaven]

OK, so it has been a week and half since I froze these. I've stored the post-frozen bottles in a large tub on their sides, and in that time I've had three out of about 50 bottles seep from the caps (given the high pressure from lack of total yeast death). Not one bottle bomb. Additionally, the vast majority have kept the same pre-freeze carbonation levels. So this works, albeit not as effectively as the stovetop method. For if the yeast were still active and the freezing only made them dormant, then I should have a tub full of bottle bombs given the temperatures and available sugars. Moreover, I refroze the bottles that were seeping from the caps, and that stopped the seeping. So freezing does work.

Why is this different from frozen yeast banks? If you follow the link I posted before, you'll notice that the advice on doing that successfully requires minimizing water combined with the yeast and instead keeping the yeast immersed in glycerin which does not freeze at the same temperature. Freezing by itself does not kill yeast, it is the crystals that form in with the yeast that burst the yeast cell walls.

Hence, it seems absolutely unnecessary to rebottle if one finds gushers when looking to use the stovetop method. It is a bit cumbersome to wait a couple hours to freeze 15 bottles at a time, but then again the stovetop method is cumbersome too. Moreover, if it's winter, all one needs to do is stick them outside. The trick is to let them freeze solid but not stay frozen for so long that the expansion will cause the bottles to crack.

 

[ColoHox]

Freezing is not a reliable way to kill (and I mean kill dead) yeast, or most microbes for that matter. And I'm sticking to it. You said it yourself:

I've stored the post-frozen bottles in a large tub on their sides, and in that time I've had three out of about 50 bottles seep from the caps (given the high pressure from lack of total yeast death).

Glad it worked out though, that could have been one messy experiment. I'd be curious to hear what happens if you let them warm up, some gushers I bet.

 

[nobeerinheaven]

Freezing is not a reliable way to kill (and I mean kill dead) yeast, or most microbes for that matter. And I'm sticking to it.

Sure, it's not perfectly reliable. But the alternative most people face when looking at gushers is to fully re-bottle, which takes an hour or more (plus the hassle of sanitizing, etc.). So I'll take a slightly less reliable method that saves me a lot of work, personally.

I'd be curious to hear what happens if you let them warm up, some gushers I bet.

Warm up to room temperature or warm up, say, past 85 degrees Fahrenheit? They have been kept at about room temp. for the past two weeks. And my thought is that at a certain point the gushers will turn into merely highly carbonated drinks (my theory is that gushing is a transient state that occurs when the c02 pressure at the top of the bottle is much higher than the pressure elsewhere, e.g. in the beverage itself).

 

[nobeerinheaven]

OK, I got some bottle bombs last night. So do this at your own risk.