How to Make Lacto-Fermented Mustard (Two Ways)

by Kaitlynn Fenley
Two small jars of fermented mustard on white background.

Learn how to make two types of fermented mustard with our Easy Fermented Mustard Recipe. This recipe includes two options for flavor, traditional mustard, and German mustard. You can easily add this fermented mustard to sandwiches, burgers, wraps and salad dressings for probiotic benefits.

Easy Recipe for Fermented Mustard

The way we ferment mustard is different from vegetable fermentation processes. Since mustard seeds are a dry good, they need to be fermented in a different way to ensure a safe, preserved product. For this recipe we used already acidified, probiotic sauerkraut brine in addition to raw apple cider vinegar to create probiotic mustard.

When I make mustard from scratch, I always let it ferment and age for about a month. The aging process helps to cut the initial bitter flavor. Mustard seeds and mustard powders are initially very bitter and with time the bitterness dissipates.

two small jars of fermented mustard with a wooden spoon in one jar. Sourdough bread and a blue napkin surrounding the mustard.


  • Mustard Seeds and Mustard Powder: Obviously, this is the main ingredient in mustard. I like to use a mix of brown and yellow mustard seeds with yellow mustard powder. Once the mustard is done fermenting, I blend it in my blender for a smooth texture.
  • Apple Cider Vinegar: I think raw apple cider vinegar is the best for this recipe. You can also use white vinegar or rice vinegar.
  • Sauerkraut Brine: You can use the brine from homemade sauerkraut or you can use the brine from our Cultured Guru Sauerkraut.
  • Sea Salt: As always, I suggest using unrefined sea salt. Any type of unrefined sea salt works well.
  • Horseradish: I LOVE horseradish in mustard recipes. I think the flavor pairs so well with mustard seeds. You can use horseradish powder, but I suggest using fresh horseradish usually found in a jar in the refrigerated section of the store.
  • Maple Syrup: Most mustard recipes call for a type of sweetener, usually sugar. I prefer to use 100% pure maple syrup instead of sugar.
  • Spices: This recipe requires Garlic, Onion, Tarragon, Cinnamon, and Turmeric.

How to Make Lacto-Fermented Mustard

I prefer my mustard to be lacto-fermented for three main reasons. The first being digestibility. Sometimes I like to go overboard with the mustard on veggie burgers and sandwiches… and that sometimes results in a bit of indigestion. BUT when it’s fermented, I have no issues. So more mustard, fewer problems! yay! Next, I prefer the flavor. Mustard is a very flavorful condiment, but did you know that when it’s fermented the flavor is even better?! Lastly, I love making this fermented condiment because it’s an easy way to add some probiotic bacteria to any sandwich or burger.

Preparing the Ingredients

You’ll need to have sauerkraut brine ready for this recipe. You can make sauerkraut using our homemade kraut recipe, or you can purchase sauerkraut here.

two jars of fermented mustard (one white and one yellow) on a white background.

Easy Fermented Mustard Recipe

This fermented mustard recipe includes two options for flavor, traditional mustard, and German mustard. You can easily add this fermented mustard to sandwiches, burgers, wraps and salad dressings for probiotic benefits.

  • Author: Kaitlynn Fenley
  • Prep Time: 10 minutes
  • Cook Time: 0 minutes
  • Total Time: 10 minutes
  • Yield: 16 oz 1x
  • Category: Condiments
  • Method: Fermentation
  • Cuisine: German



Mustard Base Ingredients

  • 50 Grams Yellow Mustard Seeds
  • 50 Grams Brown Mustard Seeds
  • 100 Grams Mustard Powder
  • 50 Milliliters Sauerkraut Brine
  • 75 Milliliters Apple Cider Vinegar
  • 50 Milliliters Filtered Water
  • 5 Grams Sea Salt
  • 2 Tablespoons Pure Maple Syrup
  • 2 Tablespoons Horseradish

Spices For German Mustard 

  • 1/8 Teaspoon Cinnamon
  • 1/4 Teaspoon Tarragon
  • 1/2 Teaspoon Garlic Powder
  • 1/2 Teaspoon Onion Powder

Spices For Regular Mustard

  • 1 Teaspoon Garlic Powder
  • 1/4 Teaspoon Turmeric Powder



  1. In a clean bowl, combine all of the mustard base ingredients. Stir until evenly combined. 
  2. Choose which spices to use, either the combination for german mustard or the combination for regular mustard. 
  3. Mix in the spices until evenly combined. For smooth mustard, add the contents to a blender or food processor and blend until smooth
  4. Add the mustard mixture into a sterilized, clean mason jar.
  5. Secure the lid and leave at room temperature for 48 hours. 
  6. After 48 hours, stir the mustard, replace the lid, and store the jar in the fridge for 4 weeks. This is a slow cold fermentation, aka the aging process. This process will eliminate the initial bitter flavor of the mustard.
  7. After 4 weeks you can use the mustard on sandwiches, on burgers, in salad dressing recipes, etc. 
  8. Store for up to 6 months in the fridge. 


*to sterilize a mason jar, boil the jar and lid in hot water for 3 minutes and allow to cool. 

Keywords: easy, fermented, mustad

You may also like


Vanessa February 13, 2021 - 2:33 pm

Thanks for sharing! Can I freeze it?

Cultured Guru Admin February 13, 2021 - 4:38 pm

I’ve never tried, but I think freezing it would be okay. Have you ever frozen mustard before?

Letizia January 29, 2022 - 9:22 pm

Would omitting the horseradish cause any issues?

Kaitlynn Fenley January 31, 2022 - 9:45 am

no it wouldn’t cause any issues, the flavor will just be a little different

Julia February 4, 2022 - 8:11 am

thank you for the recipe! I was looking for some ingredients to the mustard of “insane in the brine”. will try your recipe. I only wonder which the ingredients of the german mustard makes you think of german food? Most types of mustard (unless bought in a special shop) here (in Germany) consist of only mustard (plus vinegar, salt, sugar), but nothing else.

Kaitlynn Fenley February 4, 2022 - 8:22 am

You’re welcome. It’s not that any particular ingredient makes me think of German food… I just picked up some mustard labeled “German mustard” from the grocery store, read the ingredient label and then recreated it, but made my recipe fermented.


Leave a Reply to Kaitlynn Fenley Cancel Reply

Recipe rating