I would like to be able to can and then sell my own hot sauce. The hot sauce I make is a low acid meat (ground beef) and tomato based sauce. I had sent it in to get a shelf life expectancy, and was advised the acidity level was too low and the only way I could make the sauce in a way that it was shelf stable was if I used a retort or sold it as a frozen product. Neither of these are options I can consider at this time.
While you can add things to your product to make it shelf stable, most of them are either going to be prohibitive to use at a small level or they will significantly change your sauce. For instance, industrial preservatives like calcium proprionate can be used as a preservative in some meat preparations, but the usage level is usually around .1-.4%, which would be very hard to deal with in small batches.
Other preservatives would either increase the acidity or decrease the water activity of your product. These would be things like vinegar, citric acid, salt, sugar, grain dextrins, etc, all of which would change the flavor of your sauce.
An aseptic packaging product (such as Tetra Pak) might work, but if you can't consider freezing, that might be out of your reach too.
Low acid products must be pressure canned. Products intended for sale must be canned in FDA registered facilities and typically inspected by a state regulator. Many areas still have community canneries with some being FDA registered and state inspected where you can prepare your product with equipment that is well suited to the task. These community canneries have staff on hand who can teach you how to use the equipment and offer pointers while helping you adhere to any applicable regulations. The best way to locate nearby community canneries is to contact your local county extension office or university agricultural extension / food science program.
Edited to add an example of a community cannery: http://www.co.hanover.va.us/works/cannery.htm
Sauces must be high acid with a pH below 4.3 I would suggest lower to be safe. Also high salt levels this will reduce the water activity. The goal is a water activity below .85 17% salt will get you to approximatly below 0.90 which will inhibit many pathogens, but not molds. pH below 4.3 and 17% salt is safer.
Do not attempt to use preservatives such as sodium propionate or calcium propionate (these are mold inhibitors) and things like benzoates and sorbic acid are more wide spectrum, butthese will only inhibit and things that can grow in an atmosphere without oxygen can kill you. Botulism is of a high concern.
High fat helps, and to combat the effect of higher acidity level on the flavor of your sauce, look again at the ingredients of condiments on grocery shelves; there are spices and fruit that go into balancing the flavor at high acidity.
Xanthan gum helps thicken and keep out air, providing once you add it you don't whip any more air into your sauce (use it after all blending and grinding and the sauce has had a chance to release air).
Lecithin help blend your ingredients, it's an emulsifier, and coat proteins to protect from oxidation.
I use those two along with citric acid to keep my homemade mustard and pepper sauces for years in the refrigerator. They'll do well on the shelf as long as they've had air removed and it's not too hot. Even then, worst case of being opened and put back in a hot environment, only the top got a bit funky.