That's a long time to have left tomato sauce in a pot. Whether it is safe or not depends on the type of pot and the conditions under which it was stored, as well as whether or not it grew anything in that time frame. Personally, I wouldn't risk it.
My understanding was you can get Botulism from ANY improperly canned foods, meaning the seal was not air-tight.
That sounds like mold. They might not have been processed properly.
it means the tomatos are gone ofNot necessarily true. According to the Penn State Extension office:Seed Discoloration - Canned TomatoesA consumer brought in a jar of home canned tomatoes to the office (canned last year). Some, but not all of the seeds have turned black. Is there any danger in using these tomatoes? ANSWER - If the seeds began to discolor during storage, it is probably not a sign of spoilage as long as the product was processed correctly and a vacuum, indicating a tight seal, has been maintained. It may be a reaction of harmless polyphenol compounds in the seeds with iron or other minerals in the water.http://extension.psu.edu/food-safety/food-preservation/faq/seed-discoloration-canned-tomatoesAccessed January 25, 2013.
What ever the date on the can say's, or if no date about 1 year
Home canned goods can be safely kept until the lid starts to rust or the seal is broken, but really should be used before the next harvest. Commercially canned stuff usually carries a best-by date. I wouldn't use it much past 6 months later.
Fresh tomatoes might last a week. Home canned - about a year. Commercially canned - several years.
NO as in heck NO
Tomatoes can be preserved using just a Boiling Water Bath. However in the last 50 years or so, many varieties of low-acid tomatoes have been created which could be trouble for long term storage. If you use a Boiling Water Bath, then most modern recipes call for a Hot Pack (boil the tomatoes, and jar them hot); plus add 2 tablespoons of lemon juice (or 1/2 teaspoon of citric acid) per quart. Once sealed in Mason jars, boil the jars, completely covered in water, for 45 minutes. Your other choice for long-term storage is Pressure Canning (not covered here). If you intend to use them within a week, neither of the above is necessary. Simple refrigerator storage is fine.
For home canned foods, figure on one year for the best quality. That should take you from harvest to harvest. Make sure the goods are properly stored - cool, dry and no sunlight:
A 303 can of tomatoes refers to a specific size of canned tomatoes, typically measuring 303 in diameter by 407 in height, which holds about 16 ounces (or 1 pint) of product. This size is commonly used in the food industry and by home cooks for convenience. The label "303" is often associated with the contents being whole, diced, or crushed tomatoes, making it a versatile ingredient for various recipes.
MOST PROCESSED CANNED VEGETABLES HAVE A STABLE SHELF LIFE OF 2 YEARS. EXCEPTIONS WOULD INCLUDE ACID BASED CANNED VEGGIES; LIKE TOMATOES, TOMATO SAUCES , WHICH MIGHT SPOIL & CAUSE THE CAN TO SWELL OR LEAK AFTER AWHILE.
HOME CANNED FOOD HAS ITS BEST FLAVOD THE FIRST YEAR.It can be used for several years later.Its a judgment factor for the canner.