The recipe below marked a major shift in the way I thought about cooking. Now my default assumption is to make things from scratch, and if I am buying a prepackaged "ingredient", I question whether I might be able to make it myself while saving money and making a higher quality product. Usually the answer is that I can! Before, I didn't think about having options beyond store brand vs. name brand. Ketchup was always super-sugary and nutritionally negligible. Yes, I was one of those kids that liked ketchup on everything, even though I despised tomato sauce.
I made this first because it sounded interesting and I am always looking for more things to eat lacto-fermented/probiotic, but I was ruined after the first taste. Now I cannot go back to store ketchup. It tastes awful to me in comparison. Even friends who are put off by some of the unfamiliar things that I eat (such as organ meats) have begged for this recipe.
Have you ever had leftovers or homemade goodies spoil? One of the easy-to-overlook differences between homemade and pre-processed foods is that home cooks do not normally add preservatives. Sometimes we forget that real food spoils, sometimes quicker than we anticipate. Lacto-fermentation has been used for thousands of years by regular people in low-tech settings to preserve foods, so it comes as no surprise how easy and effective it is. Fermentation also enhances the nutrient content of many foods. The basic idea is to set up a good environment for lactobacilli to flourish, add some lactobacilli directly or wait for wild microorganisms to take advantage of the setting, and then these bacteria produce natural preservatives, chiefly lactic acid. Many people think of alcoholic fermentation when they hear about fermenting something, and it is the same basic idea but uses different organisms that thrive under different conditions. Lacto-fermentation (also sometimes called salt pickling) results in only teensy bits of alcohol production, if any - well under 1% - so have no fear that ketchup will give you a buzz.
One note with ingredients: It is tricky to get tomato paste that isn't packed in endocrine disruptors, and endocrine disruptors are undesirable, especially if you consume them regularly - which you do if your food touches nearly any kind of plastic! Even BPA-free containers typically contain other similar compounds, so a non-reactive container such as glass is a much better way to go. I want to make ketchup in the future by cooking down tomato sauce to a ketchup-y consistency since it is easy to find affordable tomato sauce in glass jars, but so far I have only used tomato paste.
The fish sauce, allspice, and cloves in the recipe are very important for getting that distinctive ketchup flavor. I have used only cloves and that works well, but it is worth adding the others.
Adapted from this recipe.
6 oz. tomato paste (the Bionaturae brand has tomato paste in glass jars)
1-2 T. liquid whey*
1 T. apple cider vinegar
2 T. blackstrap molasses
1 T. raw honey
1/2 t. unrefined salt
1/4 t. ground cinnamon
1/8 t. ground cloves
optional but encouraged: 2 T. fish sauce (made from anchovies and found in Asian markets - no, it isn't "fishy" or gross at all) and/or 1/8 t. ground allspice
any other seasonings you like: garlic powder, a little cayenne, a hint of mustard, etc.
Mix all ingredients together. Taste. If necessary, add more vinegar or sweetener and adjust the seasonings. Then add water gradually until the desired consistency is achieved; I end up adding about 1/3 cup.
Pour into a glass jar and screw on the lid. Leave out at room temperature for 2-4 days to allow the good microorganisms in the whey to ferment it slightly (which is not likely to change the taste in this recipe). Store in the refrigerator. I still have ketchup made from a huge batch last summer in my fridge right now - no mold, no grossness, and it still tastes great! I cannot guarantee that yours will last this long but I think you can expect at least a few months, unless you eat it before then.
*Whey: This is the probiotic "starter" to ferment your ketchup more easily and successfully. You can leave this out, but in that case I recommend refrigerating your ketchup immediately and using it up very quickly before it spoils. This is not powdered whey you can purchase but must be separated from yogurt or a similar probiotic dairy source. To obtain this, set some yogurt in a colander lined with a paper towel, thin dishcloth, or handkerchief. Place this over a bowl to collect the whey that drips out. Leave out for several hours or overnight. This should result in up to half the yogurt dripping out as whey, which will keep for several months in a lidded glass jar in the refrigerator, and the other half remaining in the colander and thickening to resemble cream cheese. This "cream cheese" is a good probiotic substitute for cream cheese, by the way, and lasts a couple of weeks if refrigerated.