So, apparently making my own ketchup is considered ambitious. I still say it is surprisingly easy. Take tomato sauce, a bit of tomato paste, vinegar, sugar, water, and some spices mixed up in a small crock pot/slow cooker and leave it simmer uncovered most of the day. Once it's cooled completely, taste and add a few more spices if necessary. Then, bottle it up.
homemade ketchup bottled up and ready to use
Seriously, that's all it took ... the big element is the time it simmers. Just remember to stir it a couple times an hour, or you'll end up with the bottom corners carbonized. While I did start with a recipe ... I actually only measured the sugar and vinegar, while guesstimating the tomato sauce and paste and just winging it on the spices. I also used pomegranate vinegar instead of distilled white, and that adds a bit of zip.
Hubby's verdict is: this is good. No need to buy any more at the store.