Recently, a group of people went to a church potluck dinner in Ohio. Of the 77 people who dined, one died, 11 had to be put on a ventilator to breathe, and another 17 fell ill. What happened? Well, the normal food safety rules that apply to restaurants and other places that serve food to the public don’t apply to church functions. As such, one of the cooks used the boiling water method to can (preserve) some potatoes. (Potatoes, a low-acid food, should be canned using a pressure cooker.) Those potatoes then got used to make potato salad for the gathering. Unfortunately, the potatoes were tainted with spores of the soil bacterium Clostridium botulinum and the pot luck attendees were poisoned by the botulinum toxin.
Why am I bringing this up? Because — as I’ve written about earlier — some homebrewers do something similar when storing their wort. Homebrewers who use the boiling water bath method of canning yeast starter wort, or use the no-chill method of cooling and then store the wort for extended periods of time, are running a similar risk of botulism.
I’m not going to rehash everything from the first two articles I’ve posted on this topic. I’m just adding the information above as further evidence that botulism is real and it can be lethal.
Don’t Fret, Just Avoid the Problem
The good news is that when brewers use standard brewing procedures — boiling their wort, chilling it, and promptly pitching their yeast — there is no risk of botulism. There’s never been a recorded case of the botulinum toxin in beer or anyone getting sick from it. The only way this could happen is if you use the boiling water method to can wort for a yeast starter, or store no-chill wort for an extended period of time. (I would guess that 3 days is the longest you should do this, but that’s a guess. Pitching as soon as the wort is cool enough should suffice.) These things would never be done at a commercial brewery, and that’s a huge part of why botulinum toxin has never been found in beer.
The degree of risk associated with storing boiled wort is not known. In the US, the number of deaths each year due to botulism poisoning (the median is 23) is less than the number of deaths due to lightning strikes (the average is 93). I’ll hazard a guess that you don’t live in fear of getting hit by lightning. Neither do I. But I’ll also guess that when a thunderstorm approaches, you don’t grab a metal tennis racket and climb the nearest tree, either. It’s just common sense. Even if you did climb a tree with a metal racket, the risk of getting hit by lightening is low. It’s low, but it’s also a dumb risk. And sensibly, you avoid it . . . or at least hopefully you do. (Personal anecdote time: When I was in high school, I knew a kid who climbed a tree with metal tennis racket racket during a thunderstorm. Did he get hit by lightning? Yes. Yes, he did. Did we all make fun of him when he got back to school? Yes. Yes, we did. On the other hand, once my high school friend Brian and I went golfing. Midway through the round, a storm blew in. Did we head to the clubhouse? No. No, we did not. We golfed in the rain until we heard this announcement over public address speakers: “Brian and Chris. Your mothers called and said to get off the course.” Did we get hit by lightning? No. But is it hard to look cool strolling into a clubhouse after an announcement like that? Yes. Yes, it is.)
In the case of managing the risk of botulism, there is a simple solution. When you boil wort, cool it quickly and pitch your yeast promptly. That’s it. You are now completely safe from botulism poisoning (and free to climb whatever tree you want). The risk was small, tiny really, but avoiding it was also easy. (Also, by “promptly,” I mean don’t let the wort sit for days before you pitch, which you wouldn’t do anyway.)
If you must store wort, use a pressure canner to preserve it. (Freezing would also work, although refrigeration won’t.) The proper canning procedure for low acids foods (including wort) is almost exactly like hot water canning except that you use a pressure cooker. It’s not that difficult. So don’t risk poisoning yourself — and certainly don’t put other’s lives at risk — for a small bit of added convenience. Brew safely, everyone.