Updated: Nov 27, 2022
DO NOT look at your food. I mean it! Don't do it!
Okay okay... I'm trying to say; don't obsess about what the food inside the jar looks like after you're done processing it and it's cooled. Newbies tend to pick apart everything about the product they've canned and very often it leads them choosing not to eat their food that they spent so much time and money on. (I've been there.)
You've researched what you want to can and how to process it. You've mastered using the equipment you've purchased. You have purchased or grown the best ingredients you're able. You have packed and processed the food according to USDA recommendations. The jars have sealed and you're ready to wash the jars and store them for when you want to eat it. But....
There's a weird black spot inside the jar... is that mold? A fly that got in? A speck of pepper? Or just a piece of food that overcooked next to the glass. Remember that the inside of that canner gets to 240 degrees; that's going to burn food when it's hanging out by it's lonesome on the side of the glass.
There's a white film all over the chicken.... that must be mold. I drained all the fat off. Well, no ya didn't. It's impossible to get all the fat off the food prior to canning. There's fat still inside the meat and that fat will migrate outwards as the food and jar cool.
When we buy cans of food at the store, we cannot see inside. For some reason, as a society, we tend to trust the faceless people that canned the food in the factories over the cleanliness and effort that we did ourselves. Stop it. Your kitchen and processing is far cleaner than the food factories are able to be. Go read some articles about the B, and find that most infections happen from commercially canned food.
Home canned food has lightyears more nutrition and doesn't include alot of the franken-ingredients used as preservatives in the commercial food supply. Trust what you've learned and the skills you have to accomplish this for your family.