Wash ripe tomatoes thoroughly
Remove stems and any damaged spots
Cut tomatoes into quarters
Place tomatoes in a large pot
Cook over medium heat until softened and juicy
Stir occasionally to prevent sticking
Mash the tomatoes as they cook
Strain through a food mill or fine sieve to remove skins and seeds
Return the strained tomato pulp to the pot
Simmer on low heat, stirring often
Cook until the mixture becomes very thick and concentrated
Add a small amount of salt if desired
Spread the paste on a baking sheet for faster reduction if preferred
Continue cooking until it reaches a dense paste consistency
Cool completely
Transfer to clean jars or airtight containers
Refrigerate for short-term storage
Freeze in small portions for long-term storage