Here's a homemade tomato ketchup recipe that uses roasted tomatoes for extra depth of flavor, as well as three kinds of vinegar.
This ketchup recipe calls for 6 lbs of fresh ripe tomatoes. You could also use a combination of fresh and canned tomatoes for this ketchup recipe. (See note below)
- 6 lbs tomatoes (about 12 large tomatoes, but see note)
- ½ cup sugar (brown)
- ¾ cup onion (finely chopped)
- 2 cloves garlic (finely chopped)
- ½ cup red wine vinegar
- ½ cup cider vinegar
- ½ cup balsamic vinegar
- 1 tbsp cayenne pepper (or to taste)
- Preheat oven to 450°F.
- Halve the tomatoes, drizzle some olive oil over them and roast them on a baking pan (or two) for 20 minutes or until they're soft and wrinkled looking but not burnt.
- Let the tomatoes cool for a few minutes, and then transfer them to a blender or food processor and puree until they're smooth. You'll likely have to work in small batches.
Tip: Use care when processing hot items in a blender as the hot steam can sometimes blow the blender lid off. Start on a slow speed with the lid slightly ajar to vent any steam, then seal the lid and increase the blending speed.
- In a heavy-bottomed pot over a medium heat, warm the sugar, keeping it moving with a wooden spoon, for about a minute.
- Add the onion and garlic, the pureed roasted tomatoes (and the canned crushed tomatoes, if you're using them). Reduce the heat to medium-low and cook for 10 minutes.
- Add the three kinds of vinegar and continue to cook for another 20 minutes or until reduced by two-thirds. The ketchup should be well thickened by now. Remove from heat and season to taste with the cayenne pepper.
- Strain the ketchup through a mesh strainer lined with cheesecloth and into a plastic container.
- Cooling: Fill a large stockpot about halfway with a mixture of half ice, half water, and submerge the container in the ice bath to chill. The idea is for the ice-water level to come most of the way up the outside of the container, but don't let any water into the ketchup.
- Stir the ketchup more or less constantly, until it the temperature reaches 70°F on an instant-read thermometer. Then remove the container from the ice bath, cover and transfer to the refrigerator where it will keep for about 10 days.
Note: You can substitute canned crushed tomatoes for some of the fresh tomatoes in this ketchup recipe, but it's best to use at least a couple of pounds of fresh tomatoes; the roasting process brings out the flavor.
If you want to substitute canned, keep in mind that one 28 oz can of crushed tomatoes is roughly equal to four large, ripe tomatoes.