Canning - real life help

Rappel

Sun, Aug 18 2019, 1:18 am

If you can food regularly:

Do you really replace the covers every time? I'm not sure how much of it is the Ball company being overcautious, or whether the covers really won't hold a seal a second time.

Also, if you like making grape preserves, I'd love to hear your recipe!

amother

Navy

Sun, Aug 18 2019, 2:28 am

The reason you shouldn't reuse the lids is because the rim of the jar might not be precise from one jar to another, and once the lid is "shaped" to that specific position on that specific jar, it might not get a perfect seal the next time even though it looks fine.

BadTichelDay

Sun, Aug 18 2019, 4:47 am

When you write canning, do you mean preserving jams, fruits etc. in glass jars?
I have been re-using old jam jars for years successfully (as have my mother and grandmother before me). In my experience, one nearly always gets a good vacuum even with old shop bought jars that previously contained commercial jam. And if the vacuum doesn't work, you can easily feel it on the lid and just put those into the fridge and use them up first.
However, I'd do this only with sweet, sugary homemade jams for reasons of food safety. I'd never can vegetables, meat etc. at home because of the Botulism risk.

Tried grape jam once: 50% grapes, 50% sugar, dash of lemon juice, pinch of cinnamon. Turned out a bit too sweet though.

Rappel

Sun, Aug 18 2019, 4:55 am

Really? There's no risk once you've added sugar and lemon?

My sister gave me some nice canning jars, and I just made a load of good tomato sauce, and I'm making grape jam with the kids today. But it would seem a mighty waste to throw away the canning covers after only one use, so I came here to see if all those recommendations were just being overcautious

BadTichelDay

Sun, Aug 18 2019, 5:18 am

As I wrote, I've been re-using old lids forever, but the day after jam making, when it's all cooled down, I feel and prod all the lids carefully to make sure the jars all have vacuum. There's always 1-2 that don't.

High sugar content (like 50%), to my knowledge, prevents Botulism growth. The worst that can happen is that it goes moldy and that is clearly visible.
Did a only round of lemon jam this year, from our own lemons. For citrus fruits like lemons, oranges and etrogim, I use 2/3 sugar on 1/3 fruit. All other fruits 50-50 ratio.

Whenever possible, I keep even the vacuumed jars in the fridge - can't get myself to trust the hot climate. In the old country, we had an underground basement that stayed cool all year round. But here, with more than 30 C in the kitchen cabinets most summer days...

BadTichelDay

Sun, Aug 18 2019, 7:09 am

Hmmm, just gave it a bit of google research. Turns out that the real safeguard against Botulism is the acidity of fruits rather than the sugar. That's also why vegetables are more at risk - less acidic. Unless one adds vinegar or similar.

Seems the "family minhag" of adding a bit of lemon juice to jams makes sense after all (I always thought it was to reduce foaming).

Happy canning day to you, anyway.
And never, ever ever eat from a can with a bulging lid, bubbling or positive pressure inside, says Doctor Google.

Rappel

Sun, Aug 18 2019, 7:32 am

BadTichelDay wrote:

Whew, then my tomatoes should be safe. Still going to toss some lemon in though. This is my first time canning, and I'm pretty leery of everything that could go wrong.

BadTichelDay

Sun, Aug 18 2019, 7:50 am

Tomatoes were specifically mentioned on a few websites as low-acidity and therefore at risk if canned without added acid.

Another thing - I fill the jars with boiling water to (sort of) sterilize them shortly before using them. The lids go all together in a bowl with boiling water.

Maybe check for yourself as well - there are lots of websites about safe home canning.

By the way, another risky homemade food is spiced oil. Putting herbs or garlic into olive oil to flavor it and then keeping it is also Botulism territory and not recommended, unless one keeps it refrigeated and uses it up in a day.

amother

Mint

Sun, Aug 18 2019, 8:20 am

Follow tested modern recipes from Ball or other reputable sources.

Do not use heirloom recipes. Fruits had different amounts of naturally occurring sugars and acids years ago. Tomatoes have far less acid nowadays than they used to.

Use bottled lemon juice if using it for acidity rather than flavor to sure you get the right amount of acid.

Sterilize everything before starting and follow times/temps carefully.

Lids may be able to reseal, but I wouldn't risk it. I do use old lids for things that are not sealed, such as homemade yogurt. The lids sometimes stick down when I make yogurt, but they're not really sealed and the food is not shelf stable.

There are plenty of grape jam and jelly recipes available, but I have not seen one for preserves.