It’s a safe bet that most Americans love ketchup, but put the word “fermented” in front of anything and people get a little freaked out. It shouldn’t be a scary word because people eat fermented dairy all the time, it’s just called “cultured” dairy instead of “fermented” dairy (this would be yogurt, sour cream, kefir, cheeses other than fresh cheeses, etc.). So if it makes you feel better, just think of it as cultured ketchup.

Fermented Ketchup,

Fermented Ketchup

What is fermented ketchup? Like any fermented food, it’s a food that has had its nutrients made more available and shelf-life extended by the addition of probiotics, a.k.a. good bacteria. “The word ‘ketchup’ derives from the Chinese Amoy dialect ke-tsiap or pickled fish-brine or sauce, the universal condiment of the ancient world. The English added foods like mushrooms, walnuts, cucumbers and oysters to this fermented brew; Americans added tomatoes from Mexico to make tomato ketchup” (Nourishing Traditions, Fallon, pg. 104-5). It now makes sense to me why the Brits call it “tomato ketchup” and Americans just call it ketchup!

Why do I want to make my own ketchup? For a crazy person like me I want to learn to make everything from scratch. But for the normal person, considering the availability of organic, HFCS-free options available, what is the benefit? I don’t have an ingredient label in front of me, but from what I recall, even the “good” organic ketchups use either agave (which might be worse than HFCS) or cane sugar that has had all its trace minerals removed. It is also made with white table salt, and not real sea salt, which means it’s been bleached and processed in a way that removes the trace minerals and probably leaves toxins in the salt. That puts the condiment into the “negative” category in my mind, nutritionally speaking, meaning that instead of adding nutritional value, it uses up your nutrient stores to process the food, leaving you with less nutrients than before you ate the ketchup.

So what’s in homemade ketchup that makes it nutritionally “positive?” For the sweetener, we use organic, Grade B Maple Syrup. It’s the dark stuff, so you know it has all of the vitamins and minerals it had when it came out of the tree (Grade A is lighter in color, sweeter, and less nutritious. Those lucky enough to live in Europe can sometimes find Grade C, which is highest in nutrients). For the salt, we use sea salt. Real salt is not white because it is not pure NaCl. The “impurities” are trace minerals that our body needs but can’t get from other places. The next ingredient harkens back to ketchup’s distant roots: fish sauce (and yes, even our fermented fish sauce is homemade, we just reused the bottle of a commercial fish sauce). Don’t worry, it doesn’t taste fishy, it just adds a ton of nutrients and some saltiness.

The final ingredient–the one that ferments the ketchup–can be a few different things. In Nourishing Traditions (my favorite cookbook) the recommended fermenting agent is liquid whey. Since some people are seriously sensitive to any dairy product (casein in this case), there are a couple of substitues. I have successfully substituted kombucha in equal parts, and for our next batch I want to try using sauerkraut juice as the fermenting agent.

So here’s the recipe:

Fermented Ketchup Ingredients,

Fermented Ketchup Ingredients

Fermented Ketchup


  • 3 cups canned tomato paste (preferably organic, BPA free can, approximately 5 6oz cans)
  • 1/4 cup whey, kombucha, or sauerkraut juice
  • 1 T sea salt
  • 1/2 cup maple syrup (I use a bit less)
  • 1/4 t cayenne pepper
  • 3 cloves garlic, peeled and mashed
  • 1/2 cup fish sauce

Directions: Mix all ingredients until well blended. Place in a quart-sized, wide-mouth mason jar (or multiple smaller jars). The top of the ketchup should be at least 1 inch below the top of the jar. Leave at room temperature for 3-4 days before transferring to refrigerator.

Ketchup has always tasted nice, but this ketchup is a real gourmet treat. And I know that when I add it to eggs, liver, or burger patties, that I’m adding probiotics and nutrients to my food! It’s a condiment you can feel really good about consuming. Now I just need to figure out a good recipe for homemade fries! I’ve heard you can fry them in duck fat, and I want to try that!

Have you ever made condiments at home? Does the fish sauce in this recipe scare you away?