Wash your fresh tomatoes and remove the stems.
Chop the tomatoes and remove their seeds, and then wash them again.
Place the chopped tomatoes in your blender or food processor and pulse until you have a smooth puree.
Place your sieve over your saucepan and pour the puree over it.
Bring the puree to a semi-boil over medium heat.
Once the puree is about to boil, turn the heat to medium-low or low.
Allow the puree to simmer and reduce for 30 to 45 minutes, making sure you're stirring occasionally.
Add the other ingredients and stir.
Let the mixture simmer for another eight to 10 minutes, making sure you stir occasionally to avoid burning.
Once the mixture has a similar consistency to ketchup, remove your pan from the heat, and allow it to cool.
Once cool, transfer your simple homemade ketchup to your small container.
You can now use your homemade ketchup! When not in use, make sure you seal the bottle tightly and store it in your refrigerator.