In a large pot with lid, mix all ingredients together and heat on medium-high stirring frequently until it just comes to a boil.
Reduce heat to very low, cover and allow to simmer for 2-3 hours until color darkens and the sauce becomes thick. Stir occasionally.
Allow to cool completely, then pour into an airtight container and store in the refrigerator, however this sauce with keep unrefrigerated for up to two weeks.