Beer Forum

Newb question: I have never canned and don't know the first thing about it. I was wondering if you could fill a mason jar with wort and put it under boiling water for 15 min and call it good? If you can't do that with wort to make it sterile enough, will it work for water for yeast washing?

Westco

I've probably been canning wort longer than anyone else here so I guess I'm qualified to answer. The short answer is no on the wort and yes (though why bother?) on the water.

When making wort you are basically creating an almost ideal growth medium for microorganisms. Most, but not all, can be killed by simple boiling. One of the major ones not killed is botulism. This needs to be killed by temperatures higher than what can be achieved by simple boiling. This is also an anaerobic organism, i.e. it grows in the absence of oxygen. Hot water bath canning like you described creates just such an envioronment.

To kill these spores, you need to do your canning under pressure to achieve a temperature of around 250°. The spores themselves are not toxic, but when they reproduce they produce the deadly toxins. These toxins cannot be destroyed by cooking.
In wort you are using right away, this is no problem since the presence of oxygen (needed by the yeast) retards the spores until the yeast reproduces enough to crowd out the few spores that may be present aided by the alcohol that is also produced.

Check around at yard sales and pick up a used pressure cooker. I generally see them for $15-$25. I make up my starter wort 5 gallons at a time (all grain) and can it all. This will stay good at cool room temperature for over a year. It really speeds up the time to get a starter going.

Hot bath canning will work for water for yeast washing since it is relatively clean to start with. However, it is so easy to boil and cool the small amount of water you need, it hardly seems to be worth the effort. Even yeast washing, in my opinion, is of marginal value. Something that you probably try a few times to say that you have tried it, but it is doubtful your beer will benefit much. If your yeast really needs washing, you probably should look at the process you use for moving wort from the kettle to the fermenter. There are all sorts of ways to minimize the amount of trub getting to the fermenter.

Wayne

I agree with everythin in Wayne's post except:

Bugeater wrote: These toxins cannot be destroyed by cooking.

Fortunately, the protein of which this toxin is composed is easily denatured by fairly brief exposure to temperatures above 80 °C (5 min at 80°C, 1 min at 100°C will do the job). Low pH canned foods are inherently safe because the low pH kills the bacteria and they can't produce toxins. Note that the cutoff pH is generally accepted as being 4.6 but that growth at lower pH has been observed. In any case, wort pH usually isn't that low. Higher pH foods must be cooked at higher temperatures to kill the bacteria. It takes appreciably longer to do in the spores. So to be absolutely safe, boil anything canned before you eat it. Especially if you canned it yourself.

Bugeater wrote:yes (though why bother?) on the water.

Sterile water is very convenient for rehydrating dry yeast, blooming gelatin, and resuspending/washing yeast cakes.

I believe Wayne's point was that, although convenient to can sterile water, it is just as easy to boil and cool the relatively small amounts of water one would need for using dry yeast and blooming gelatine.

Alan

My bad, I got in a rush and missed the details at the end of Bug's post.

Thanks for the detailed post!
Westco