Savvy home canners work with one over-riding credo, French Fries: When it doubt, throw it out!
Boutulism toxin is colorless, odorless, and tasteless. There is just no practical way it can be tested for at home.
But, if you do a little research on actual cases, it's also not the bug-a-boo USDA has built it up to be. In the past, even CDC has taken exception to USDA's paranoia in this regard.
I'm working from memory, so don't quote these numbers. But they're probably close. And easy enough to check on.
Boutulism cases are remarkably stable, year to year, averaging something like a total of 23 cases with a food borne causation. Of those 23 cases, about half come from home-preserved foodstuffs.
So, let's call it 12 cases. They result from 3-4 events. That is, if four people get sick from eating something----say, for instance, a mother and three kids sharing a jar of something--- that's four cases but only one event. And, as it turns out, most of those events deal with food that was held or stored improperly after opening. So what we're looking at is 3 or 4 specific jars of "bad" food.
Now lay that against the multi-thousands of home-canned and home-preserved foods that are produced every year. I don't know a single insurance company that would even keep actuarial tables on that sort of "risk."
I don't mean to trivialize boutulism. It's a horrible thing to suffer. But look at the risk-odds vs the to-do USDA makes over it, and you have to wonder why they focus so heavily on that one potential problem. And, if it's so risky, how come USDA doesn't try to get honey banned as food? Honey is loaded with boutulism bacteria, which is why it is not recommended for infants.
At base, as with any home preserves, you have to weigh the risk/benefits and decide for yourself. I make no recommendations either way, other than the credo stated above.
