Bubbly tomato sauce?

April 16, 2007 10:05 AM

Why was my jar of tomato sauce under pressure and the sauce bubbly? I had a half-full jar of tomato sauce that was closed and refrigerated. When opening the jar in order to use the sauce, the air pressure inside the jar was higher than the air pressure in the room and air escaped with a woosh, similar to opening a bottle of carbonated liquid (like seltzer.) Bubbles developed in the sauce in the jar, and a quick tasting of the sauce revealed that the sauce caused a sensation similar to carbonation. What was going on here?
posted by andrewraff to Food & Drink (16 answers total)

It's gone bad. Toss it.
posted by Steven C. Den Beste at 10:12 AM on April 16, 2007

The pressure and carbonation were indeed carbon dioxide, created by microorganisms in the tomato sauce doing their metabolic thing.
posted by Steven C. Den Beste at 10:18 AM on April 16, 2007

Yuck, don't taste stuff that's gone off like that. If it's botulism, that little taste can be enough to kill you.
posted by bink at 10:33 AM on April 16, 2007

See also
posted by grouse at 10:41 AM on April 16, 2007

Best answer: Your tomato sauce fermented, and you shouldn't eat it. (BUT, don't worry about botulism: botulinum bacteria can only survive in anaerobic environments, therefore could not be present in an already opened jar of tomato sauce. There are, according to the CDC, less than 25 cases of food-borne botulism poisoning in the US per year and most of them come from improper home canning.)
posted by agent99 at 10:42 AM on April 16, 2007

Some detail (and stern warnings about consumption, natch) from a recent, similar question.
posted by cortex at 10:48 AM on April 16, 2007

You might be thinking "But it was refrigerated!" Actually, there are a lot of microorganisms which do just fine at those kinds of temperatures. Lager yeast, for instance, thrives at 40 degrees F, though I'm sure that's not what got into your tomato sauce. There are a lot of fungi which do well at those temperatures (which is why my cheddar cheese turns green sometimes).

It would probably take a lab test to find out for sure what did get into it, but it doesn't really matter. It's gone bad. Toss it.
posted by Steven C. Den Beste at 10:49 AM on April 16, 2007

Ah, hell.
posted by cortex at 10:49 AM on April 16, 2007

On the other hand, you could have a start on making tomato pruno!

Even I would toss it, and I'm "OCD" about wasting food; if somebody wants a disgusting booze-type beverage, well, if you're not in prison you can buy Cisco.

And I agree you shouldn't taste food you think might be "off", regardless of what might be causing it; I get my Highly Sensitive "SO" to sniff it for me instead.
posted by davy at 11:00 AM on April 16, 2007

By the way, my interdimensional "SO" tells me that cooking or microwaving food you think might be off still won't make it safe, because while it might kill the germs or molds it won't kill the toxins they produce.
posted by davy at 11:07 AM on April 16, 2007

Seconding the "don't worry about botulism": your tomato sauce is likely too acidic for C. botulinum.
posted by penchant at 11:16 AM on April 16, 2007

I used to work for a food company that sold various tomato products. One of the products was a 50 gallon bag of tomato sauce, to be sold to restaurants and such. Occasionally, these bags would explode in the trucks during delivery. The truck drivers had to report this, and take pictures of the inside of the truck with the exploded bag, for our records. Viewing those pictures was a great perk of the job.

I am not sure of the chemistry involved, but I highly doubt it's botulism. Tomato products seem to do this sometimes. Ever since I had that job, I have been opening my tomato products carefully.
posted by veronitron at 11:31 AM on April 16, 2007 [1 favorite]

Response by poster: Well, I certainly won't go and taste food that looks funny anymore. I did smell the sauce first, and it smelled normal. ( I did dispose of the remaining sauce, because I'm not that much of an adventurous eater, but am curious about the cause.)

I'm not sure how I missed the question from last week about the exploding hummus.
posted by andrewraff at 11:42 AM on April 16, 2007

Best answer: I did smell the sauce first, and it smelled normal.

Smell is not a good test for dangerous contamination.
posted by solid-one-love at 1:09 PM on April 16, 2007

"Smell is not a good test for dangerous contamination."

Let's all tell Santa we want chemistry sets!

Seriously, if it smells okay, looks okay and tastes okay, how can you tell if it's spoiled or not? (And I thought tomato products were too acidic for botulism but I'm no chemist.)
posted by davy at 11:54 PM on April 16, 2007

Seriously, if it smells okay, looks okay and tastes okay, how can you tell if it's spoiled or not?

But in this case, it didn't look okay.
posted by grouse at 2:56 AM on April 17, 2007