New at canning... Air bubbles?
I found air bubbles in a rhubarb jam we made. Sad to say the unopened sealed jar had begun to mold about a week after canning.
Gave canning another shot this time with pickled radish. In with the radish went onion, garlic, celery, fennel, peppers. I did not know about the needed 5% acidity for the vinegar, and went with a recipe that called for water to be added to the vinegar. After the canning process I noticed that I had watered down vinegar that had a 5% acidity.
The jars have now sealed properly (concave). But when I tip the jar, and let the liquid run through the veggies, I get a few air bubbles that float to the top. The bubbles don't grow like the do in sparkling water or champagne, but act a bit like soap (rise to the top, then after a bit they pop). Note that not all of the jars have the bubbles.
Do I need to worry about these bubbles?
This is my second attempt at canning and would like to make food not poison. So, any tips you can toss my way would be very helpful.
I think I read on here (i'll try to find the post) that bubbles were ok as long as they were not moving. In my short canning experience, that has been pretty true. i did strawberries this weekend (which I wouldn't recomend) and they have some bubbles....but again, I always test stuff myself before giving away and leave them on the shelves with out bands to see how they do...but again, I am not an expert....:)
I don't have a perfect method to recommend for getting rid of the air bubbles except persistence.
With a jam-like product, let it sit in the pot for a minute or two and stop bubbling before you fill your jars. Then, take a tiny rubber spatula or a chopstick, and repeatedly slide it down the inside of the glass, then push towards the center while watching the product fill up the space you've cleared against the wall of the jar. While doing that you're trying to fill in the space in the center that might have air, and also making sure not to introduce new air spaces. Also give the jar a good tap on the counter (upon which you've put a potholder or a folded dish towel).
For lumpy-stuff-in-juice like your pickled radish, you need to take more care when you fill the jars. I bumped and poked and manhandled my maraschino cherries when I was filling my jars. Also with these products it's handy to use the non-wide mouth pint jars with the shoulders--then you can jam the solids in and they'll stay in place when you pour in the liquid and mess around with it.
Maybe the next few times you try out canning you can put your finished product into the fridge for a few days, then check for bubbles. That way everything you made will still be in good shape even if you didn't have perfect success.
You are doing the boiling water bath, right? You can give the stuff an extra five minutes in the water over the recommended time, to see if extra bubbles get driven out.
Your canned items should not have bubbles in them. The bubbles are, of course, pockets of air trapped in the mixture. The best way I know of to eliminate this is to make sure they're vacuum packed (special jars and lids - I use BALL) using a boiling water bath, checking the temperature over the proper length of time, then sealing so that cooling creates a vacuum chamber. I prepare a fair amount of rhubarb but I don't can it so I can't speak specifically to that canning process. I do believe, however, that it would be included among the high acid group of foods.
Your Ball jar supplier should have things like bubble removers and head space measuring tools. Some foods (low acid varieties) require a specific length of time at 240 degrees (or more) and a pressure cooker is the only way to achieve those temperatures in the canning process.