How to Make Ketchup. It's probably never occurred to most people to make their own ketchup, but by doing so you can achieve a distinct and unique flavor. See Tips for ideas on customizing this recipe. Makes between 2 and 4 c., depending on tomatoes and cooking times.
Stem and roughly chop the tomatoes and place them in a nonreactive pan.
Add half the vinegar and a few pinches of the salt and bring the mixture to a boil.
Cook for 5 minutes, mashing with a wooden spoon.
Strain the liquid into a saucepan without pressing on the solids.
Press the solids into another saucepan by forcing them through the strainer, leaving the seeds and skins behind. Rinse the strainer. You can puree the tomatoes before straining, if necessary, but they should be soft enough to press through the strainer screen.
Stir the sugar into the solids.
Add all the remaining ingredients to the liquid.
Bring the liquid to a simmer and cook for about 20 minutes, until very syrupy.
Strain into the solids, and bring to a simmer, stirring well. Simmer for 5 more minutes or until the desired consistency is reached. Puree with a hand blender, food processor or blender if necessary.
Taste and adjust the seasonings. The mixture should be sweet and faintly tangy; if more tanginess is needed, sprinkle in some vinegar.
The best part about this recipe is customizing it. My favorite way is to roast red bell or red jalapeño peppers, skin and seed them, and substitute 2 c. of them for a third of the tomatoes. Use a little more sugar, too. (See "How to Roast Peppers," under Related eHows.) Another great modification is to grate about a tablespoon of fresh ginger, skin and all. Squeeze as much juice out of it as you can and reserve it. Add the ginger solids to step 9, and stir the liquid in at the end. Use brown sugar instead of white, and stir in about 1 tbsp. soy sauce as well. If you can find pure clove oil - which is extracted straight from whole cloves - in a specialty store, use that instead of cloves and you'll be surprised how close this ketchup tastes to the commercial variety.
Watch the mixture carefully as it cooks, because the sugar will scorch and burn if it reduces too much.