1. Put the tomatoes, Digon-style mustard, sugar or honey, vinegar, jalapeno or cayenne pepper, and mace(if using) in a 6- to 8- quart pot. Stir and bring to a boil over high heat. Turn the heat down and simmer (cook food in liquid over gentle heat, just below the boiling point, low enough so that tiny bubbles just begin to break the surface.) for at least 30 minutes until the tomatoes have exuded all their juice and the pulp has dissolved.
2. Remove from the heat, and transfer to a blender or food processor, and puree(blend) until it's smooth. Strain through a fine conical strainer or food mill into a container and refrigerate until ketchup is ready to use.
Note: The ketchup will keep for around 2 weeks in a covered container in the refrigerator. Also, it can keep frozen for up to 8 months. So you can make extra batches, and have great homemade ketchup all year long!