Traditionally made tomato paste is a rarity in this day. Ovens play too great a role in industrial production, rather than the old world method of drying the tomatos in the sun. Most tomato pastes are heavily-pasteurized to ease the canning process - Maria's is unpasteurized and hand-packed, the way it's always been done. (This means the lids won't be "compressed", like some jarred preserves.)
Maria Grammatico spreads the pulp of the tomatoes on taulieri, wooden boards seasoned with years of tomato-drying, and leaves it on her rooftop for just over a week. The thick, rich paste is then salted and packed into candari, large clay jars, and covered in fine Sicilian extra virgin olive oil. This ancient preservation method has worked for Grammatico and she sees no reason to change. A traditional snack for lucky Sicilian children is a bit of tomato paste spread on a slice of bread...simple, but perfect.