Preserves aren't real tricky, as long as you follow procedure. Foods that are acidic enough (like our jalapeno and habanero sauces and tomato-based salsas) can be canned with minimal processing (sterilize your jars and lids, hot-pack them with the finished sauce, put lids on and immerse them in boiling water for the recommended time). This type of processing creates a nice vacuum seal - very safe. It's things like beets, beans, carrots, etc that you have to be very careful with - extensive processing in a pressure cooker is required to avoid food poisoning. Simply cooking the foods and sealing them is not enough because the temperature won't get high enough to kill the organisms that produce the toxins that cause Botulism. We blanche such foods to stop enzymatic breakdown, bag them, and stuff them in one of the chest freezers. Some vegetables are remarkably tasty even after freezing. Swiss chard is one of the best.Thanks, I won't attempt it then. Someday I do hope to try doing preserves. Looks tricky, though.