Unfortunately the same brand of ketchup we have been using for years has started causing me to have a soy reaction each time I eat even the tiniest amount. Although the label hasn’t changed and soy is not listed, it’s obvious that this ketchup does now contain soy… so ketchup has been added to that ever-growing list of foods that I have to make from scratch.
Ketchup is amazingly easy to make. I usually make only a small batch at a time, but if you’re lucky enough to have lots of fresh tomatoes, larger batches of ketchup can also be processed in canning jars for longer-term storage.
I start with a 28-ounce can of crushed tomatoes, or an equivalent amount of cooked-down fresh tomatoes and juice. The fresh tomatoes are nice, but not really necessary… canned tomatoes make really good ketchup. I mix in 2/3 cup of brown sugar, 1/2 cup of cider vinegar, and 1/2 teaspoon of salt. These ingredients are always a constant for this quantity of tomatoes because the vinegar and brown sugar cooked into the tomatoes is what gives ketchup its distinctive taste.
Next come the flavorings. I usually vary the flavorings batch to batch. Today I used one medium onion, one small green pepper, three cloves of garlic, and three stalks of celery… all finely chopped. Sometimes I also add about a tablespoon each of celery seeds and mustard seeds. Next I let everything simmer together for at least an hour… or until the mixture has achieved a ketchup consistency. (We like a thick ketchup.) I taste the mixture as it cooks… if I think it needs more of something (like more garlic), I just add it in. Some people add cinnamon, cloves, coriander, allspice, bay leaves, or red pepper flakes. There are lots of ketchup recipes “out there,” but I have had really good results following the basic method I described above and adding flavorings to taste… always keeping in mind that all the flavors will intensify as the ketchup cools.
I use my small food processor to puree the tomato mixture until it is smooth. An immersion blender or a regular blender works well, too. Ketchup made with a 28-ounce can of crushed tomatoes will yield approximately three cups of ketchup, depending on how much the tomato mixture has been cooked down. I have no idea how long an opened container of homemade ketchup will keep in the refrigerator, but I would not expect it to last as long as purchased ketchup, so when I make large quantities of ketchup, I keep only a small amount in the refrigerator and freeze the rest. Sometimes I even freeze ketchup in ice cube trays so I can take out the exact amount I will be using.