Basically, I designed this recipe myself. It is not based on any other recipes, it is prepared as much from scratch as possible, since its illegal for me to make my own sherry. Basically the same deal as my other recipe's. I designed this recipe for the exclusive purpose of using it in my barbecue sauce recipe, because I will not use commercial prepared ketchup in my bbq sauce, that's just wrong. This is the solution. This is my second ketchup recipe, my first was developed over a year ago; however, the ketchup was mistakenly thrown out before I had even tasted it, and I didn't document that recipe nearly as well as this one. My original recipe was based on white tomatoes (italian ice tomatoes), this one is based on green tomatoes (green zebra tomatoes). All my tomatoes were garden fresh, none came from a can or the store. Expect more ketchup recipes in the future, as part of my continuing mission to develop a competition worthy barbecue sauce.