Jar of tomatoes is used to preserve tomatoes longer than their standard 4 days of freshness. After jarring, it is necessary to cook the jar of food in a heat source. Otherwise, the food will rot as fast as if it were not jarred.
Tomatoes cannot be eaten directly from the jar, therefore the jar must first be opened, returning the tomatoes, with their usual freshness.
Tomatoes can be pickled to preserve their lifespan by using sugar and vinegar.