Store in a cool, dry place.
After opening the can, it is better to pour the rest in a glass and keep it in the refrigerator.
Tomato paste is a pantry staple made from concentrated tomatoes that adds intense, tomatoey flavor to all sorts of dishes without adding extra moisture. Tomato paste is made from whole tomatoes that are cooked, strained to remove seeds and skins, then cooked again to evaporate moisture.
Plus, tomato paste is great for intensifying other tomato flavors in whatever you cook. Add a dollop to jarred sauce and cook it down, or throw it in a marinade or seasoning paste for chicken.