Turns out a lot of people had always wondered why black olives come in cans, but green olives come in jars. Since, of course, one wondering leads to another, our Facebook and Twitter have been alight with questions...
The science: What made black olives in jars so good for botulism? Why don’t green olives have the same problem?
That, plus the low-oxygen environment, makes a black olive in a sealed-up jar so good for botulism. Unless you kill the bacteria with high heat.
Hey, wait a minute! You can heat up a glass jar to 240 degrees. Home canners do it all the time.
True! Thanks for pointing that out. I bet I know what you’re asking next…
So, why don't the black olives come in jars?
Turns out, we may owe Mort Rosenblum an apology. He guessed that it was because green olives are prettier. He was half-right.
We turned here to Kristin Daley, vice president for corporate development at the Musco Family Olive Co.-- one of the two big olive canneries in California.
Daley says black olives are darn cute. Their brine, not so much.
“The brine is so dark that it’s barely translucent,” she says. “It’s not very attractive. So there’s not a huge benefit to putting the product into a glass jar.”
And, she says, there are costs: Jars are heavier, so shipping them is more expensive. And there’s more waste from breakage.
At this point, you may be wondering: Why is the brine so dark?
Because the olives got cooked in it, says Eric A. Johnson, a bacteriologist at the University of Wisconsin who specializes in botulism — or, as he calls it for short, “bot.”
“The heat treatment for bot spores is gonna decay some of the tissue,” he says.