I just canned a whole bunch of food for the first time yesterday. Mostly pickles and jam, but I also canned two tomato based things: spicy salsa and crushed tomatoes. I added commercial lemon juice to the crushed tomatoes and the salsa contains plenty of vinegar.
I removed air bubbles before putting on the lids, but there are now air bubbles in the product. The lids pinged, so I know a seal was formed, but I have no idea if this is normal!
— Asked by Adrienne Marisa: The reason we remove air bubbles from jars before canning is that if there's too much air in the jar, it can interfere with the jar's ability to drive out the extra air in the top and develop a good seal. Additionally, too much air space and much of the canned product finds itself sticking out of the brine/syrup/canning liquid, which can lead to discoloration and the development of off-flavors (this is the worst-case scenario though, and typically only happens if you wait a long time to use that item).
However, sometimes it's impossible to remove all the air bubbles. The goal is to do your very best at bubbling each jar before wiping the rim and putting the lid on. If you've still done your best at bubbling your jar and you find that you've still got some air bubbles, don't beat yourself up. It happens.
As long as your jar sealed, you are okay. I find that the best way to check your seal is to remove the ring and elevate the jar holding onto the lid. A good seal means that it will hold fast.
Marisa McClellan, our guest expert this week, is answering your questions on canning and preserving. Marisa writes Food In Jars, a blog devoted to canning, preserving, and other food in jars. She also teaches canning workshops.
Previous Question for Marisa:
• Is It Safe to Can Meat Sauces?
• My Strawberry Jam Went Bad! Why Did That Happen?
(Image: Flickr member sleepyneko licensed for use under Creative Commons)