Freezing vs canning
I personally find freezing more convenient, mostly because I don't know how to can, but also because I find the process of sterilizing, boiling water, buying proper containers, etc, to be daunting. My question is, is there really a difference between freezing and canning vegetables, taste-wise, cost-wise, convenience-wise, nutrition-wise, or anything wise? So far, what I've been doing is pre-blanching my vegetables before I freeze them and they turn out fine and the only motivation I would have to can my vegetables is if I ever ran out of freezer space.
I'm a fan of freezing. The reasons I don't can any more are listed in your opening sentence. My grandma used to can and she tried to teach me but I'm sure she only canned because they didn't have refrigeration, let alone a freezer. If there are any benefits for canning over freezing, armageddon notwithstanding, I still don't' think it's worth the effort or expense.
I am a big freezing fan for most things. There are a few items that must be canned (preserved lemons, certain pickles, etc.). Everyday cooking from the freezer is so much easier if you use your freezer as a tool. I freeze almost everything because there is only two of us eating. I helps minimize waste. I now organize my freezer in bins for condiments, left overs, homemade sauces, etc. I prefer freezing for small things like specialty chili's, tomato paste globs, whole lemons, blanched herbs.
I have some friends who think they know how to do canning, but I really don't trust their preservation methods so end up ditching whatever they give me. That's my guilty secret. Now if they'd given me something they'd frozen, while it was still frozen, I would have been delighted. I think freezing is so much easier and better for everybody so that is the only thing I do....chutney my latest adventure.
This is sad ... though I do have to ask, that method are they using? I am a bit hinky about eating anything my MIL has canned, but she uses a method no longer recommended by the USDA.
Do you at least open the jars? It's really easy to tell if something is off. Jams and jellies are pretty safe. If they're using a basic method, employing pectin, it's a no-brainer.
Freezing is certainly much more accessible to the home cook. If you are canning anything other than acid ingredients (jams and pickles, for example) canning needs to be done with a pressure canner and there is a risk of botulism if you do things wrong. I certainly wouldn't recommend canning vegetables to anyone who was not experienced with proper jam and pickle making.
I think the main motivation in canning would be when you want a result that is specific to canning, like pickle making, or if you didn't have access to a freezer, or if you want to transport the end result.
Energy budget-wise, you have to continually chill frozen foods, unlike canned goods, but you'd have to factor in the cost of producing the canning jars to figure out what the balance is.
We don't care much for canned vegetables - I really prefer them fresh, but I do freeze fresh corn in the summer, and when I roast squash, I'll do a couple and freeze most of it.
I do can tomatoes, though - I don't like them frozen. My mother always canned tomatoes, and I guess I'm just used to the more cooked flavor and texture, if I don't have fresh.
And I can can stocks - I find it easier to use it if it's not a frozen block - that, and freezer space has been at a premium for a while around here!
We invested in a pressure canner several years ago when we decided to start buying tomatoes at the farmers' market, and I've got to say, it was well worth the money to us. It can be a bit of a pita, yeah, but once we got the process down, it's not bad at all.