We were embarked on yet another veggie burger experiment when fellow Gastil Cooking School member Grant said, “What about the ketchup? We should make our own!”
I tried to weasel out of it, but he insisted that it would be educational, so I succumbed.
I prefer using published cookbooks to internet recipes, because I have learned which authors I should trust for what. For traditional American style tomato ketchup, I pulled out Joy of Cooking. It had a very nice recipe – for 10 pints. I promptly shoved it back again and went online.
The Joy of Cooking recipe made me realize that ketchup is really just pickled tomatoes. I don’t know why that never occurred to me before. Probably because in my world ketchup is just this red stuff you find in a bottle. But it is also a way of preserving the massive onrush of tomatoes from the vegetable garden – all that vinegar means it will keep a long time without canning or freezing.
Most of the recipes I found online called for either tomato paste or canned tomatoes, but since tomatoes are in season, and ketchup is about preserving, it seemed silly to not use fresh. We ended up using this version by Melissa Clark from the New York Times.
It calls for grape tomatoes, massive amounts of vinegar, a lot of sugar, some salt, pepper, and Worcestershire sauce. You just cook it down until it is jam-like, blend it, and strain it.
Overall, the recipe worked great, and I liked the simplicity of it. It did take a lot longer than the suggested 20 minutes to cook down (more like 45) and we ended up with considerably more than the 2 cups listed – more like 4. We were careful with measurements, and it came out the right flavor and thickness, so I’m guessing the variation might come from the juiciness and size of the grape tomatoes. I thought the amount of sugar was too high, so we initially cut it back. But after tasting the ketchup mixture, it was obvious that you need it all – otherwise the vinegar is too powerful. We stirred in the proper amount, and the flavors balanced well.
In the end our ketchup was delicious! Thick and full of tomato flavor, very like the Heinz you buy in the big red bottles, but fresher. We now have a bottle full to use with all our burger experiments.
One of the fun things about this recipe is that it is easy to personalize. You can fiddle with the seasonings and make all sorts of variations. Grant and I added a clove of garlic and a little chili paste to ours, which gave it a subtle kick.
A note of caution on cookware: I used my workhorse 15″ cast iron skillet for the job. It performed beautifully, and amazingly didn’t lose its impregnation of oil, but I wouldn’t recommend that if you are worried about iron leaching into your ketchup. 45 minutes of a boiling acid bath is sure to attack cast iron. Since I tend to be on the anemic side, it is not a worry for me.