Lacto-Fermented Homemade Ketchup

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Lots of people have emailed me over the years for a homemade ketchup recipe, and I’ve emailed back a basic, loose recipe that gets us by. But now I’m pleased to share Erin’s recipe! It offers more flavor and is lacto-fermented for greater nutrition and a longer shelf life. Enjoy! –Wardee

Is it crazy for ketchup to bring me such a smile? Honestly! I didn’t know if I should name this delicacy “Oh My Lans Ketchup!”, “Mercy Sakes Ketchup!”, or “You Are Never Going to Believe It Ketchup!”. When I think about this delicious, simple, and nutritious condiment, I can only shake my head. Can you imagine encouraging your child to take a dip in his/her ketchup? Who doesn’t love to dip? Enjoy the taste and tang of summer year round with this lacto-fermented treat! Your gut will thank you… as will each of your friends and family members! :-)

  • 12 ounces organic tomato paste (no salt added)
  • 1/4 + 1/8 cup water
  • 1/8 cup whey (or water)
  • 2 Tablespoons apple cider vinegar
  • 1/4 teaspoon mustard powder (could probably use a prepared dijon mustard if you don’t have powder)
  • 1/4 teaspoon cinnamon
  • 1/8 teaspoon cloves
  • 1/8 teaspoon allspice
  • 1/8 teaspoon cayenne
  • 1/2 teaspoon sea salt (I used larger grained salt)
  • 1/4-1/3 cup maple syrup or honey (you could even add a bit of molasses)

In a medium sized bowl, whisk together all ingredients. Pour sauce into a storage container. Cover and leave at room temperature for two days. Move to the fridge.

Oh, my! Just thinking about this ketchup makes my mouth water. When my neighbor was giving it a taste test, she suggested using it as a barbeque sauce for grilling. Excellent idea!

See also: lacto-fermented mayonnaise and honey-dill mustard, or 3 more fermented mustard recipes.

Free CHEAT SHEET: “Create Your Own Ferments” Fermenting Formulas

Want to create your own safe-to-eat and delicious fermented salsas, chutneys, pickles or krauts? Need to know how long to ferment, how much salt to add, and how to store?

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Click here to get the free CHEAT SHEET today!

This post may contain affiliate links. We only recommend products and services we wholeheartedly endorse. Thank you for supporting Traditional Cooking School by GNOWFGLINS with your purchases. Our family thanks you!


  1. Liz Joiner says

    Fantastic! I can’t wait to make this one! All the other recipes I find have fish sauce in it and that is something that I don’t even think I’m quite ready to dig into!

  2. Mary P. says

    I have always made the recipe from NT and love it, but missed some of the spices that other ketchups have. This sounds like it will really fit the bill.

    To those who are unsure about using fish sauce – don’t worry, it does not lend a fishy taste to the finished product. It gives a depth of flavor and a bit of saltiness. It also is the source of the fifth taste – umami. I will make sure to add fish sauce when I make this ketchup recipe.

  3. Patty says

    I’m wondering about some substitutions. Honey for the maple syrup and sauerkraut juice for the whey. Any reason why those won’t work?

  4. Erin says

    Patty- I agree with Wardee. Sounds great. I also think it would be nice to use molasses for part of the sweetener, especially if the ketchup is going to be used for barbeque sauce. :-)

  5. Erin says

    Jana- I wish I could give you an exact time. I know we finish our homemade jars much sooner than a regular bottle of ketchup because it is good on so many things, and we feel so good using it. I’d say at least a month and probably longer. If you are concerned, just give it a smell. Your nose will tell you! :-)

  6. Erin says

    Stacy, Liz, Kat, and Mary- Thanks for your enthusiasm! It really is delicious, and so easy to make. Hope you enjoy it like we do! :-)

  7. Kelly Holderby says

    Perfect timing! I’m almost out of ketchup. I’ve been making the NT recipe, but this sounds like it’s definitely worth a try. I’ll be using sorghum syrup in it.

  8. Erin says

    Kimarie and Kelly- I’d love to hear how you like the recipe. It’s an easy one to tweak if it’s not quite perfect for you the first time. Hope you enjoy it! Makes me want to go on a mission showing everyone how easy it is to make lovable homemade ketchup!

  9. says

    Last summer I made a plum chutney that I have been using as ketchup all year. The original recipe came from The Cottage Smallholder but I wrote up my version on my blog. This looks like a super easy, great tomato ketchup.. I might try it soon! Thanks!

  10. Rachel says

    Lacto-fermented, I would imagine this should last a good 2 months or more in the fridge…in the unlikely event you don’t finish it off well before then!

  11. Monica says

    THANK YOU ERIN!! I have been wanting to make my own ketchup for my daughter and have been hesitant cuz all recipies have whey in it. she can’t have it. :-( I am sooooo looking forward to trying this!

  12. Erin says

    Rachel- Thanks for your comment. I agree. I’m guessing it’ll even go longer than that. No spoil prone ingredients like raw eggs! I can’t believe how fast our ketchup disappears! :-)

  13. Malana says

    This recipe sounds great! Do you know how I could use tomatoes from my garden in it? This amateur doesn’t know how to change tomatoes into tomato paste. :-)

  14. Kylie NZ says

    Okay, I am totally crazy about every recipe Erin posts. Here is another great one I can not wait to try! Added to the list of sourdough pizza crust, sourdough skillet pancakes.. love love love! Keep them coming! : )


  15. Erin says

    Kylie- Thank you so much for the smile! You are very sweet. Hope you enjoy the ketchup as much as we do. :-)

    Anjanette- This recipe could not be easier. In fact, it’s easier than going to the store and waiting in a line to check out. :-)

  16. Erin says

    Malana- Oh, how I would love to have enough tomatoes from our garden to consider making tomato paste! I did a little looking for you and came across a great website. Looks like 5 lbs. of tomatoes will give you around 2 cups of paste. The process involves cooking the tomatoes, pushing them through a sieve, and finally slow baking the sauce in the oven to remove the water. Oh delicious! If you are overrun with tomatoes, give it a try!
    Here is the link-
    Good Luck!

  17. Malana says

    Thanks so much for the link about tomato paste. I’m certainly going to give it a try if we have a bountiful harvest. I can’t wait for my tomatoes to be ready!!
    Thanks for sharing your wonderful recipes. The sourdough pancake recipe also looks delicious. I need to get a sourdough starter to try it, but I used my cast iron skillet for just basic pancakes and they were better than usual. :-)

  18. Amy says

    THANK YOU for posting this! Question for you- how do you know the fermentation process has worked? Does it taste a little sour? I can’t have whey so will be using other things to kick off the fermentation process, and am just wondering how I will know when it has worked. Thoughts?

  19. Erin says

    Amy- The apple cider vinegar will also ferment the ketchup. Leaving it on the counter for three days should do the trick. And, to be honest, I don’t really know how you know if it is working. I just trust that it is (based on information in the Nourishing Traditions book and other fermented recipes I’ve read), but that isn’t a very good answer now, is it! :-) I know the ingredients are nourishing, and that fact alone makes me smile inside and out!

  20. says

    Thank you so much for sharing! We don’t normally use it, but I have grandchildren for the summer and they need it for everything! What a timely post this was and I am heading to the store for some tomato paste. :)

  21. Karen says

    Erin, You mentioned you will be going through PA this summer? We live near the Wilkes-Barre/Scranton area. Will you be close to me? So far our summer has been very good.
    We have been getting the sunshine and rain showers just when we need them to make
    everything green and gardens growing nicely. You can email me. Thanks.

  22. Kelly Holderby says

    Just made this and it is truly delicious! I’m going to add it to my recipes in Springpad.
    Thank you so much!

  23. Kylie NZ says

    My my my. This is good good good. This is officially my new ketchup recipe. I have always used the NT one, which was alright, but this is delicious! It hasn’t even fermented yet and I couldn’t even stop having little spoonfuls!
    What are your favourite places to use it?
    I bulk buy my tomato paste in a bout 5 pound containers, then freeze it in 1 1/2 cup portions (12 ounces). When ever my ketchup runs out, I pull my jar of paste out of the freezer, and make up a new batch. I just had the thought while making this, it would be SO much more time efficient to make up a massive batch of this ketchup when I first get the tomato paste, then freeze it. When I run out, I simply pull one out of the freezer already made, rather than making a new batch every time. Thanks for another stunning recipe Erin!

  24. Erin says

    Kylie- So very glad you enjoy the ketchup! Isn’t it good! I still shake my head when I think about it! And, I think your idea to freeze batches is great. I should do that. We go through it so fast. We’ve enjoyed this ketchup with salmon patties, fried potatoes, burgers, meatloaf… so many things. Delicious! :-)

  25. Monica says

    Erin – ok, I did it. just hope I did it right! I used raw coconut water vinegar, cuz my daughter can’t have apple cider vinegar and I put the metal top with the seal on the jar and twisted it on to sit out for 2 days on the frig. Should I have used a towel? we live in florida, so as soon as 48 hours were up, in the frig. it went. it smelled nice, no, it smelled really nice, so ate some. I love it. :-) My daughter has day’s where she loves it and days when she doesn’t love it, depending on her mood :-) it was so easy to do. the hardest thing was hoping I’d remember when to put it in the frig. ha ha. My husband’s question was “does it taste like real ketchup?” I thought so, so said yes, you try it and tell me. he hasn’t yet, but I am sure in time he will since I won’t buy a new bottle of the “real” ketchup right away. ( oh I’m so bad….)

  26. Erin says

    Monica- Sounds like you did it just right! Glad you enjoy it! Hopefully your husband will give it a try soon. :-)

  27. Lisa says

    how much does this make? Maybe I missed it? Looks yummy and easy – but I want to make sure I got the right size containers ready :)

  28. Erin says

    Hi Lisa- It makes a little more than 2 cups. I usually fill my 2 cup ball jar and then have a little bit left over in a smaller jar. Enjoy!

  29. Ceitllyn says

    There was a question posted about using a lid versus a towel but I didn’t see an answer. I am new to fermenting, so could you let me know. It would be a great help. Thanks loads :)

  30. says

    Ceitllyn – You can do a towel or a lid. I’d prefer a lid, since this lacto-fermentation happens without the presence of oxygen and there’s no need for air flow, which just introduces more organisms to settle on the top of the ketchup and possibly proliferate.

  31. Janette says

    Hi. Just a quick question about fermenting and what room temperature is best? I am finding that during the summer months it is too hot and my lacto fermented sauerkraut doesn’t turn out right. Does anyone have any info on this? I am thinking temps in the low 70’s is best but during the summer it gets in the 80’s in my kitchen. Any ideas on this? Thanks!

    • says

      Janette — Best is right around room temp. Over 80 degrees and things go very fast. My ferments last weekend (during hot weather) were done in half the time. So 1-1/2 days instead of 3 days. Very fast! We were enjoying 100 degree weather outside and the house was almost as hot. So, if you have a hot kitchen, keep an eye out for mold (skim it off the top), and be prepared for things to be done soon. With something like ketchup, you won’t know it necessarily, like you would a pickle. I made this ketchup last weekend and since everything else was done fast, I considered the ketchup done too.

  32. Michelle says

    I made this today & was very pleased with the taste. I have always enjoyed the NT recipe too and I am not a fish lover at all. I use half the amount of fish sauce called for, use water for the rest, and the taste is nice and not at all fishy. But this was great too! I think maybe next time adding some molasses, garlic and paprika or chilli powder might make a really good BBQ sauce…I will post if it works! I made this is the food processor as it mixed the honey in better. I was wondering if ACV can be used to sub for whey in other ferments too? I know it can when soaking grains; I didn’t realize that it was an option for ferments though..
    This filled.maybe 5/8 of a quart sized jar,so I am guessing doubling it would be too much for producing a quart since you need the empty space at the top. Has anyone tried?

    I don’t know about the freezing idea mentioned above …wouldn’t it destroy the live enzymes/good stuff you are trying to create by doing the lacto-fermnting process? .

  33. Erin says

    Michelle- So glad you enjoyed the ketchup. Your comment, however, has pointed to a bit of editing I must do! Whey must be used in the ketchup if you want it to be lacto-fermented. You may omit it, but then you would not reap those benefits. The ACV is added for taste. I’m sorry if that was confusing.
    Your BBQ sauce idea sounds amazing. I have yet to give that a try. Please let us know how it goes. Delish!

  34. Michelle says

    OK, so it is lacto-fermented with the ACV and the whey but would not be if you used just the ACV and water, right?

  35. Erin says

    Yes. The whey does the work. You could leave the ACV out completely, use the whey, and have a deliciously nutritious lacto-fermented condiment! :-) Enjoy!

  36. Mala says

    By tomato paste do you mean raw tomatoes blended and pureed or did you make the paste by cooking the tomatoes first?
    Thanks in advance for your clarification.

  37. Erin says

    Mala- I purchased organic, no salt added tomato paste from the store. If you want to use your own tomatoes, you have to go through the process of cooking them down first. Check out this recipe as an example or the many others on the web. Good luck and enjoy the ketchup!

  38. Mala says

    Wow I appreciate your prompt reply, thanks. I couldn’t find the link for the tomato paste recipe in your reply though.

    Would it suffice to simply steam, puree the tomatoes, pass it through a coarse filter, and then cook down the puree again to ketchup consistency, then cool it and carry on with the recipe to make ketchup?
    Thank you once again!

  39. monica says

    i was so bummed to read that the ketchup is not lacto-fermented without the whey…. is there any other thing I could use to make it lacto-fermented? Thanks. :-)

  40. radiantfusion says

    Monica, whey is needed for lacto-fermentation in this kind of recipe. However, it is easy to get whey. Just hang plain yogurt (with live cultures) in a cheese cloth for about 8 hours. The yellowish liquid that drains out is whey, and it stores in the fridge for about 6 months. What’s left in the cloth is yogurt cheese, which can be salted and eaten like cream cheese (I add chives, too).

  41. monica says

    Thank you radiantfusion for your reply. I understand how to get whey, I was just wondering if there were other sources for getting whey. :-) like could I get whey from coconut yogurt? or can you only get whey from dairy sources? hope I am asking my question correctly :-)

  42. maria says

    Hello, and thank you for sharing the blessings God has given you so that we too can enjoy His bountiful offerings the way He intended. Tomato paste, as opposed to tomato puree, isn’t widely available here in England, and the only brand i’ve found does unfortunately contain added salt. If I use it for this recipe, could I just omit the salt listed in the recipe, or is it there as a preservative as well as seasoning? Many thanks in advance, God bless

    • says

      Holly — I had some last 6 months and it was still good for longer I am sure. It wasn’t opened very often at the back of the fridge. Opening it more will reduce the storage time.

  43. B. says

    To the person who wanted to know if there’s an alternative to whey: I’ve used the juice from home make sauerkraut to lactoferment lots of savory recipes. It’s perfect for ketchup. Delish.

  44. monica says

    hello B.

    oooh, that does sound yummy. thank you. I am not up on what can make something probiotic, so would that also make the ketchup probiotic?

    • Toni Legates says

      That sounds wonderful. I don’t always like the flavor of whey and I do love the fermented cabbage juice Idea. I can’t wait to try this sounds fantastic! Thanks for suggesting it!

    • Chris says

      Monica the whey contains bacteria from the fermentation of the milk when making cheese or yogurt. When you put this into the mix the bacteria will reproduce making the ketchup come alive with this healthy bacteria, hence the probiotic nature.

  45. Julie Rossberg says

    I’m excited to find this recipe for lacto-fermented ketchup. However, I was surprised that you can lacto-ferment something which has been cooked first. The lactic acid-producing bacteria survive the cooking process O.K.? It is the whey and salt which preserves it, and it gets new, live lactic-acid producing bacteria from the air, our hands, and/or??? ! Thanks for your responses!

    • says

      Julie — Yes, you can lacto-ferment something which has been cooked first. But since the naturally present organisms have died you MUST add a starter culture — from whey or a non-dairy starter culture. That’s why this works. :)

        • says

          Julie — No, you can’t use raw ACV. It’s the wrong culture for this kind of fermentation. Well, having said that, you could probably do it but it wouldn’t be lacto-fermented, it would be more vinegar-fermented.

  46. Chana says

    Thanks for this recipe – it sounds yummy! Question…. if I use water instead of whey, do I need to add more salt or add some type of culture?

  47. Brenda says

    I just put some ketchup out to ferment. I started with the NourishingTraditions recipe, but tweeked it quite a bit with a little apple cider vinegar and cloves, garlic and onion powder, but was still wondering what it was missing. Next time, I’m trying this one!

  48. Nicole says

    i made this last week, used a recipe from cultures for health which said to sit out for 3-5 days. My hubby put it in the fridge after the right amount of time since I had to go out of town. I got home and tasted it today and what started outta sting like my grandma’s homemade ketchup before fermentation now tastes like home-brew…. :(. Any hints for what to do different next time????

    • Ross says

      Did you get an answer about the “homebrew” taste of your ketchup? From my experience as a home brewer it is necessary for containers used for fermentation to be spotless. This is not to suggest the container you used was dirty but there are wild yeasts and bacteria floating around all over (think about how sour dough starter is made). It is possible that your ketchup was “infected” with some wild yeast and that resulted in the off taste..

  49. Eve says

    This is THE BEST ketchup ever!!! I can hardly make and ferment it fast enough for my girls, to whom ketchup is a major food group onto its own – but with this recipe, I don’t mind! Thank you for sharing your recipe!


    • Erin says

      Hi Eve- Thank you so much for your comment. I’ve been off-line for a bit, but I am so glad you enjoy the ketchup! :-)

      • Esther says

        Erin- do you also have a blog? I am very curious about living in Alaska and gardening, farming, etc with its extreme cold winters and short growing season. . I’m convinced my husband and I and our little family will be moving there in the next few years and want to learn all I can now. :)

        P.s.- cant wait to try this recipe!

        • Erin says

          Hi Esther! No, no blog as of the moment. :-) Thanks for asking! Hope you enjoy the recipe and your learning about Alaska. It is a most wonderful state (filled with many farmers and some very large produce!).

  50. Janine Jozwiak says

    For a newbie, can someone tell me where I can get whey? I’m sure it’s not the whey powder you use in smoothies, is it?

  51. Mary says

    This probably a silly question, but can I use a store-bought organic ketchup and just add whey or another culture to it and allow it to ferment on the counter in a mason jar? How about store-bought salsa? Also, I was wondering if you can ferment frozen vegetables like asparagus and cauliflower. What can I say? I’m a sucker for a shortcut.

    • Jason says

      Mary, good question. I don’t see why you couldn’t use that shortcut, provided there were no preservatives (such as potassium sorbate) added. But really, is it so easy to make! If you do make it, you can also keep out ingredients such as “natural flavoring”, which is just another name for MSG.

  52. Jenn says

    We have been searching for a homemade ketchup for a while and we keep coming back to this one. I’ve even sent a few friends this way for the recipe. Thank you!

    • Erin VL says

      Yeah, Jenn! So glad you like the ketchup recipe. I have to agree. Tasty! I’ve been itching to make myself a batch of this and the mustard, lately… Fun and easy kitchen activity to do with children. Thanks for letting me know! :-)

  53. sue says

    Do you know if a vinegary kombucha tea could be used instead of the ACV? Would it make a problem combining with the cultures in the whey? Thanks.
    What is the purpose of the vinegar? Is it for taste or does it adjust the ph of the ferment correctly, until the bacteria gets jump started.

  54. Melissa says

    I am trying to lacto-fermented ketchup right now, it has been sitting on my counter for 3 days but I don’t see any bubbles forming. Does this mean that it is not working?

    • Erin VL says

      Hi Melissa~ Sounds to me like your ketchup is ready to be popped in the fridge. Don’t worry if you don’t find bubbles. If you used active whey, you should be all set! Enjoy!

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