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Aug 27, 2009 12:25 PM

Canning Roasted Roma Tomatoes

Hello all,

I'd like to put up some roasted roma's. Any tips so I don't die? I'll be using a water bath method. I was thinking roast the tomatoes with olive oil and salt. Add to wide-mouth 1/2 pint jars with fresh basil, 1 tsp of balsamic vinegar and cover with olive oil. Leave 1/2 inch headroom and boil for about 40 minutes. Any problems with this?

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  1. All my canning resources say do not use oil in canned products, so I won't try it Freezing roasted toms with olive oil and salt works great, as does packing them in jars, sealing over with more oil and storing in the refrigerator.

    4 Replies
    1. re: kmr

      Thanks for the tips. As I mentioned, I don't want to die. Can I freeze Bell jars? Seems like as long as their is some headroom nothing should go wrong.

      1. re: misterpatrick

        Can or freeze, but don't do both. If you can something then freeze it, the liquid will expand, reducing the headspace and and possibly breaking the seal. If you just freeze, a layer of oil might reduce the risk of freezer burn, but won't make them safer. Adding balsamic vinegar or any acid prior to cooking is an excellent idea.

        Roasting tomatoes (no salt, no oil) then jar and process for 40 minutes is what I do. You might get some very excited posts saying that's not enough according to some company or govt agency and you're going to die, so if it gives you peace of mind when you open that jar 6 months later, by all means cook longer. For my part, I find 40 minute canned tomatoes taste something like tomatoes, and 80 minute canned tomatoes taste like tomato sauce.

        1. re: misterpatrick

          In the store last night I saw a display of Ball jars. Some are labeled "can or freeze". If you are sure the glass jars you have can go in the freezer, you could use those. I'm assuming you mean you are going to freeze in the glass jars instead of canning. I use plastic containers when I freeze soup. Works well. Not all glass jars can go in the freezer. After reviewing their website, I think jars that can go in the freezer are wide-mouth. The description for narrow mouth pints specificallyl says they can't go in freezer.

          1. re: misterpatrick

            Leave head room and don't tighten the ring to hard until it is solid. This is a good way to use already processed lids again.

        2. There isn't enough acidity in tomatoes - roasted or otherwise - to safely can them in a water bath. So you're best to freeze this. I understand wanting to use jars, but you'll have a better use of space if you freeze the roasted tomatoes in heavy duty ziplock bags, flattened to get all the air out. The packages are flat, use very little space in the freezer the they thaw in minutes when you want to use them. I've frozen stuff in jars also, but for something like this I recommend the bags.

          2 Replies
          1. re: Nyleve

            Just to clarify, tomatoes (home grown or commercial) can be safely canned in water bath with the addition of a small amount bottled lemon juice. Any good canning reference (Ball, county extension office, etc) has the particulars. The bottled lemon juice is more uniformly acid than fresh-squeezed juice, so don't substitute. Freezing is certainly easier, but if you are short on space (we raise beef and lambs, so freezer space get tight), water bath canning is a safe and tasty alternative.

            1. re: kmr

              I have done that also but I'm not sure that it's the same with roasted tomatoes as with a saucy tomato sauce. When I do roasted tomatoes, the mixture is quite thick and really very sweet. They caramelize in the oven which concentrates the sugars. I can't imagine adding acid to that without it affecting the flavour (not in an especially good way). I do understand what you're saying, though, and I know it's possible to can tomato sauce or whole tomatoes in a water bath safely.

          2. Definitely do not can if you're using oil. Oil will encourage the growth of bad guys at room temp, even if processed.

            I lay my gutted tomatoes (I do cherries but I've done romas too) cut side up on a cookie sheet, salt & pepper, sprinkle on garlic and fresh Italian chopped herbs, drizzle with olive oil and then roast at 250 degrees for 2-3 hours or so until the tomatoes are a little dehydrated and wrinkled looking. After they cool I pack them in snack size baggies (holds a lot of the little buggers), squeeze the air out and freeze in a single layer. When frozen the baggies get stacked in a plastic box and put back in the freezer.

            You will probably have a nice amount of oil and spices left in the bottom of the pan. Pour this off and consume with a nice crusty bread with supper or in the next day or so, or immediately as the cook's reward!