Set a medium to large pot of water on stove to boil.
Fill a bowl full of very cold water.
Rinse off fresh tomatoes.
Place tomatoes in boiling water for about 1 minute.
Move tomatoes, with tongs, from hot water into the cool water bath.
Peel off skins and core tomatoes.
Dice tomatoes and place in measuring cups.
Continue steps until you have about 15 cups of tomatoes.
Drain out excess liquid from diced tomatoes.
Place tomatoes in a cooking pot on stove, add vinegar and seasoning mix.
Bring tomatoes to a boil, then turn down to a simmer for 10 minutes.
Ladle salsa, using funnel, into cleaned jars, leaving about 1/2 inch of room on top. Wipe lip of canning jars clean. Cover with lids and seal with rings.
Place canning pot/pressure cooker on stove. Fill with 5-6 inches of water. Add salsa filled jars. Cover jars with water, covering by an inch or so of water.
Place lid loosely on canning pot/pressure cooker. Bring canning pot/pressure cooker to a boil. Turn down heat and gently boil for 40 minutes.
Turn off heat. Remove lid. Allow jars to cool slightly (15 minutes) before removing and allowing to cool completely on counter.
Store your beautiful salsa jars in pantry or on shelf out of direct sunlight! Makes around 8 pints