So. I'm canning tomatoes this morning.

[hippywife]

I canned a few pints a couple of weeks ago, too. My previous canning experience has been pickles and jams. Never tomatoes before.

Does anyone know how you can tell if a jar of canned tomatoes has gone bad? Just in case...for future reference, are there any telltale signs?

:hi:

[zabet]

1. The one I had go bad this year....

looked separated.....watery on the bottom and the 'maters all at the top. Plus the top had popped <----------that's the easiest way for me to tell. :P

[hippywife]

2. I don't think the seperation

in and of itself means that it's bad. The ones I canned a couple of weeks ago were separated from the beginning. But if they weren't to begin with, then that could be a sign, too. This new batch isn't that way, tho.

http://www.pickyourown.org/canning_tomatoes.htm

Why do my tomatoes separate from the liquid?

A frequent problem is the separation of water from the tomatoes. Why does the water separate from the solids in tomatoes?

Scenario 1 - liquid at the top and solids at the bottom

Home canned tomatoes, tomato juice, and tomato sauces with liquid at the top and solids at the bottom is quite normal. It only reflects that the juice was made prior to heating. For example, the tomatoes were chopped, run through the steamer, sieve, or food mill while still raw and prior to heating.

As soon as they are chopped or crushed, enzymes start to break down the pectin that helps to hold tomato cells together. The enzyme that causes separation is activated by exposure to air and inactivated by heat. In commercial production, tomatoes are flash heated nearly to boiling in a matter of seconds, using equipment not available to consumers. Because the pectin holding tomato cells together is not exposed to air when cold, it remains intact, and a thick bodied, homogeneous juice is produced.

The solution is to leave tomatoes whole or in large chunks (do not chop). Heat before chopping or juicing to minimize the separation.

The best way to do that at home is to heat quartered tomatoes quickly to boiling temperatures WHILE crushing. You can also heat the blanched, peeled whole tomatoes in the microwave, then crush them!

Make sure the mixture boils constantly and vigorously while you add the remaining tomatoes. Simmer 5 minutes after all tomatoes are added, before juicing. If you are not concerned about juice separating, simply slice or quarter tomatoes into a large saucepan. Crush, heat and simmer for 5 minutes before juicing.

Scenario 2 - liquid at the bottom and solids at the top (note the photo is step 10)

What about the reverse: liquid at the bottom and solids at the top? That indicates too much preheating (more than 5 minutes). Pectin breaks down when it is overheated; then separation results. If separation occurs, just shake the jar before opening or decant the water off.

[zabet]

3. Interesting....

I have not had separation in any except the one that went bad. Just lucky I guess cause I definitely ain't no kitchen guru. ;)

[Tesha]

4. I haven't canned tomatoes since forever..

I worry too much... but I remember that if you do everything right (and I'll bet you did), watch for the top not to pull down.

I gave up on it and only freeze sauce now.

[Warpy]

5. As long as you've got a good vacuum seal

meaning the tops are pulled downward, you should be fine.

It's very rare for them to go bad with anything anaerobic because the acid kills all that stuff off.

Just give them the sniff test when you open them. If they don't smell really bad, they're not bad. Extra insurance is boiling them in whatever you're making for five minutes. If there's a botulin toxin in there anywhere, boiling for 5 minutes renders it harmless.

I never had any go bad, although there were occasional ones I needed to reprocess because the lid didn't seal properly.

[hippywife]

6. Thanx, Warpy.

They did all seal fine. I will recheck them before I used them.

Appreciate it. :hi: