Crazy Jar Lady
The number one reason lids fail to seal is because of an unclean rim. And you can tell me you wiped the rims over and over and I'm telling you that rim wasn't clean. I used to use dish rags to wipe rims. I'm converted to paper towels for wiping rims now. I just add them to the compost bucket as they are soiled.
Let's look at the process:
Don't use a rag to wipe rims.
Use a half sheet paper towel, folded to create a cushioned edge.
Just moisten the edge with water or vinegar.
As you wipe a dirty rim, turn the edge of the towel over to a fresh area that is still damp.
Keep dipping into the water or vinegar to keep the towel moist.
Continue wiping with clean areas of the paper towel as you go around the rim.
If a rim isn't apparently messy, you can use the first fold of the paper towel to wipe the whole thing.
Change the the paper towel often, every couple jars.
Once the jar rim is clean, set that jar to the side so it is not mixed up with the dirty ones.
This should help keep the rims from being a cause of seal failure in your canning experience.
Now.... there's alot of debate on whether or not to use vinegar or water to wipe rims with.
Use water with products that aren't greasy. Anything fruit, veggies without meats; rims can be wiped with water. Dairy products also need to have jar rims cleaned with water only; due to curdling from the vinegar.
Use vinegar to cut the grease of any kind of soup, stew, meats, broth, etc to keep jar rims clean. Butter, lard, tallow; all need to have the jar rims wiped with vinegar to get a clean rim.
Try out wiping rims with paper towels. It might solve your sealing issue. Now.... what about when the product siphons out of the jar and the jars still seal?! Let's cover that another day.... Happy Canning!