Fermented ketchup is surprisingly easy to make. All you have to do is mix the ingredients together in a jar and let it bubble for a few days. The result is a flavor-packed condiment.
Best of all, you get to control the amount of added sugar. That’s a pretty important good thing if, like me, you use the red sauce to encourage your kids to eat their dinners. (Apparently, ketchup tastes good on everything from stirfries to broccoli!)
I realize it’s unusual to make fermented condiments. However, they are probably my favorite type of ferment. Here’s a few reasons why I make fermented ketchup:
- It’s a great source of probiotics!
- Fermentation means there’s no cooking involved. Just pack everything in the jar and leave it to do its thing.
- Homemade ketchup is a zero-waste alternative.
- The natural probiotic cultures are an easy way to preserve condiments. This ketchup will last in the fridge for upto 6 months! (Just avoid double-dipping).
However, probably the main reason why I always have fermented ketchup in my fridge is that I like all things fermented!
Quick ketchup alternative
If fermentation isn’t your thing, feel free to skip it. The ketchup can be mixed and used right away for a quick homemade ketchup alternative.
There’s only one recommend change:
- Only keep 1 cup of ketchup in the fridge at a time, and freeze the rest. Because this is a low-sugar ketchup made with real vegetables, it won’t last as long as store-bought varieties.
Whole Tomato Ketchup
The easiest way to make ketchup is with tomato paste. However, if you have a nice crop of Roma tomatoes, I recommend making ketchup with fresh tomatoes, since the flavor is far superior. (I’ve done it both ways).
It takes about 2 hours to cook the tomatoes down, so it’s a good thing to do while you watch a movie (haha).
Follow the recipe below, with the following changes:
- Replace the tomato paste with 7 lbs roma tomatoes, roughly chopped, 3 onions, diced and 1 red bell pepper, diced.
- Mix the vegetables in a large pot, and simmer over medium heat until the vegetables are very soft.
- When the vegetables a cooked, push them through a food mill (affiliate link), and return the puree to the pot.
- Add the spices and simmer for an additional hour until the tomatoe puree has thickened.
- Allow the puree to cool to at least 100 F (40 C) before adding the culture. Then proceed with fermenting as described in the recipe.
Homemade ketchup is surprisingly easy. All you have to do is pack the ingredients in a jar and let the fermentation do the work. It’s got a ton of flavor and is healthier than store-bought ketchup.
- Prep Time: 10 minutes
- Total Time: 10 minutes
- Yield: 4 cups 1x
- Category: Condiment
- Method: Fermented
- Cuisine: American
- Diet: Vegan
In the ferment
- 3 cups tomato paste
- 1 onion, diced
- 2 cloves garlic
- 1 cup raw apple cider vinegar (see notes for alternatives)
- 1/3 cup raw sugar
- 1 cinnamon stick
- 1 bay leaf
- 1/2 tsp each of allspice berries, cloves, mustard seed, black pepper
- 1 tsp salt, to taste
- 1/2 cup of water, as needed
- Mix together the tomato paste, onion and garlic in a blender or food processor. Pulse until fully pureed.
- Add the apple cider vinegar to the blender and pulse to blend. This will act as the culture for the ferment, so it needs to contain a mother. See notes for more details.
- Scrape the ketchup into a 1.5 L glass jar for fermenting (or use two 1-quart (1L) jars instead). Add in the whole spices. Cap with a loose-fitting lid.
- Place the jar in a cool and dark to ferment for 2 days (a kitchen cupboard is fine).
- After fermenting, stir in the salt. Add as much water as is needed to make a sauce-like consistency.
- Strain the ketchup through a fine-mesh sieve (affiliate link) to remove the spices. I usually bottle it at this point.
- Store the ketchup in fridge for up to 6 months. It will slowly continue to ferment, so you may need to add more sugar as it ages. Alternatively, you can freeze smaller portions of ketchup for future use.
- The sugar is added to feed the ferment. If you don’t want any residual sugar after fermenting, reduce the sugar to 2 Tbsp.
- It’s important to use raw apple cider vinegar (affiliate link). Look for “unpasteurized” or “with a mother” on the label. Alternatively, you could use acidic whey, unflavored kombucha, or other unflavored fermented beverages.
Keywords: probiotic, healthy, catsup, red sauce, vegan, gluten free, low sugar, summer, fall, homemade, DIY, quick, no-cook, zero-waste
Do you mean tomato “paste”, or “sauce”?
I do mean paste… the liquid comes in the culture, water and vinegar. I’ve also made ketchup by cooking down whole tomatoes, but it took hours! Using paste is quicker. If it seems like a lot (which it is!) just halve the recipe.
If you are looking to make tomato paste with less cooking time then after cooking tomatoes and running them thru a sieve to homogenize into a sauce you can strain sauce thru a clean and heavily rinsed undyied pillow case. This will leave you with a paste in the bag and most all of the liquid separated into a pot that you use to stretch your case over. It’s saves hours and hours of cooking. You can save the liquid for many other uses. Freeze for later use or put into a soup as part of the liquid. Paste can be used immediately or canned or frozen.
Wow! Thanks for that piece of advice. The leftover tomato water would be delicious in soup. And straining is so much more energy efficient than cooking it down. Cheers!
Could I use blended dates as my sweetener?
Dates are my favourite sweetener. And they’ll definitely work in this recipe! You could add them to the boil so they soften before pureeing. Enjoy!
Can I use dairy whey?
Yes! I’ve actually tried it. (We eat a lot of ketchup). It won’t have the same tanginess as ACV, but it will ferment!
What does it taste like ? Curious about trying it bc Im a big ketchup fan hahaha
It’s like a flavorful, tangy ketchup. The only difference is that it’s a bit less sweet than typical commercial ketchup. 🙂
Can u use sweeteners like alluose, erythritol etc?
Alternative sweeteners won’t work to feed the ferment. ACV needs to feed on sucrose, and most of the sucrose will be consumed after a few days of fermenting. However, alternative sweeteners are perfect for sweetening after fermenting. Enjoy!
Won’t the cultures be able to feed on the fructose that’s naturally in tomatoes? If cabbage doesn’t need sugar to ferment because the bacteria uses the natural sugars in the plant (carbs), then I think it should also work with tomatoes, especially since there is a much higher sugar content in them than cabbage.
Hi Jen, I have a brine-fermented tomato recipe in my cookbook. My daughter calls them exploding tomatoes since they are so sparkling and burst in your mouth! 🙂 This particular recipe uses ACV as the culture which does best with added sugar. I don’t know if you make other yeast-based ferments (kombucha, water kefir, alcohol), but they just don’t ferment well without a certain amount of sugar. However, as long as you aren’t planning on storing your fermented ketchup at room temperature for more than a few days, it’s fine to have a less vigorous ferment. Cheers! Emillie
You can use other natural sweeteners because there are plenty of natural sugars in tomatoes for the cultures to feed off of. I just researched and you can even ferment whole, uncooked tomatoes like cabbage, with salt water, and there is far less sugar because it’s not cooked down into a highly concentrated amount of sugars. I’m going to go for it with some allulose and I’ll leave feedback so others know too.
This is great! I can eat ketchup that’s good for me! Thank you for sharing this!
Glad you like it!