Make Homemade Fermented Mustard

Stories from home, 3 recipes + video demo, Down the 🐇🕳️ (sometimes the simple common foods are so much more than we might think)

Yesterday, I filmed the video for this post three times. There were some technical difficulties—luckily making mustard is quick and easy. I also was fortunate to have enough mustard seed on hand. Apparently, when Christopher had bought a pound each of brown and white seeds, the cashier questioned him with a raised brow as to his intention with the seeds. He admitted he had no idea—they were just on his list.

While I was filming, our granddaughter was with me. Providing company and commentary. She nibbled on turmeric and tasted the mustard over and over. She was quite pleased when she realized her tongue had turned yellow. She decided the one made with leftover brine was her favorite. I sent it home with her to eat with the homemade sausages her family made recently. As she was dipping in the mustard jars, I thought of how our life spirals around and around. It wasn’t until this morning when I was looking for the Bavarian-style Fermented Mustard recipe I wanted to include in this post, that I found the following vignette I’d written to go with it—when my children were still at home.

“We should never buy mustard again,” my teenage son announced when I started experimenting with homemade mustard. His older brother reacted similarly after tasting six variations in a row: “I can get behind mustard experiments. The way I see it, the more mustard you make the more we will need to have sausages for dinner.” (Note this is the father of granddaughter. The man who now makes pounds and pounds of sausage every year for his family.)

I was surprised by their enthusiastic response since my family views my culinary exploration phases as Mumsi-the-mad-scientist-is-in-the-kitchen-LOOK-OUT! Most of my experiments involve vegetable fermentation, so they never know when I will corner them, unsuspecting, with a fork full of something in my hand saying, “Here. Try this.” They are often suspicious and would like a full ingredient and process disclosure before tasting—little did they know I had also been fermenting the mustard.

I agreed that we should never buy mustard again. (I didn’t agree to more sausage dinners.) I confess this punchy condiment has been on my DIY list of things to make for a long time. When I finally did grind the seeds in a blender with a little cool water, the fresh spicy flavor released was exhilarating—especially to my sinuses. This simple blend of inexpensive seeds became a base for many mustard flavors—sweet, acidic, hotter, or herbal. I considered all the ways I could customize and make my own complex, layered flavors.

I knew I was onto something when each of the boys came to me, individually, while snacking to find out where the new mustard jars were and asked if they could have some to dollop on their beans. Certainly. (I didn’t do the mother-victory-dance until they were out of sight.)

Okay, enough reminiscing, let’s make some mustard.

One of the reasons I thought it would be a good time to share mustard making is for those of you looking for simple, handmade, consumable gifts—mustard is wonderful. It is shelf-stable (easy to send), and most people like mustard but wouldn’t necessarily love homemade ferments.

At its simplest—mustard is just a few ingredients. Pictured salt, white mustard seed, and fresh turmeric root.

Making lacto-fermented mustard transforms mustard seeds, a bit of water, vinegar, perhaps some vegetables or herbs, into a healthy real-food in the pantry staples; it is safe, and still a convenience food. And for those who love beauty—the ugly plastic yellow squeeze bottle makes way for a beautiful jar of vibrant gold.

Mustard seeds (especially the white variety) and fermentation go way back. Early on, someone discovered that these seeds have outstanding preservative qualities and mustard seeds were added to early pickled foods to enhance storage and safety. This happened in different areas of the world. In the Assam region of India there is a traditional fermented mustard called Kahudi. The seeds ground in a paste with citrus juice, wrapped in a banana leaf and left in the sun to ferment for a few days. The Latin name mustum ardens, literally meaning “burning fire”, originates in a roundabout way with fermentation—in this case, wine. Ground mustard seeds were mixed with must, freshly pressed grapes—juice, skin, and the seeds that are beginning to ferment as they convert to wine. (Incidentally, this grinding and mixing with must, and later, wine, was done directly on the plate during mealtime.)

Mustard on its own is a preservative, so it doesn’t need to go through the lactic-acid fermentation process in order to preserve the way that a vegetable does. In fact, most traditional pickles and chutneys contain mustard seeds for this reason. However, since the fermentation process benefits our foods with a rich, live-food quality, it made sense to me to use lactic-acid fermentation. This is especially nice in mustards with fresh vegetables or herbs in the ingredient list.

They are also good for you. Nutrient dense mustard seeds are high in antioxidants and high in selenium, also known to have anti-inflammatory properties. On our plates, that tasty dollop of mustard is known to stimulate the appetite and in moderation is a digestive aid because it increases the action of our salivary glands eightfold—truly a mouthwatering condiment. (Head to the 🐇 🕳️ at the end of this post for some studies.)

You will see four names for mustard seeds: yellow, white, black, and brown. “Yellow” and “white” seeds are two names for the same seed; they are brown and light tan in color. These light-colored seeds are the most common type of mustard seed.

“Black” mustard seed is a bit spicier and less common (since it requires hand harvesting) than “brown” mustard seed, but these monikers are often used interchangeably despite the difference.

The white seed is slightly larger and much less pungent than the darker seeds. When you bite into the white seed, your initial taste will be sweetness, followed by pleasant warmth. When you chew the brown seed, you will first taste bitterness, followed by aromatic heat on your tongue. Many mustard recipes mix the two seeds to provide complex flavors and control heat levels.

Three mustard recipes to get you started

I may have said one cup of water to one cup of mustard…if I did, ignore. Follow the 2:1 ratio of liquid to seed. This will give you the consistency of the mustard that squirts out of a squeeze bottle. Use more seed to liquid if you would like it thicker.

Basic Yellow Mustard, or master recipe for a mustard base demonstrated in video

Makes a little over 1 cup

To make this mustard milder, use warm or hot water in the blender when grinding. For a fun flavor variation, use any leftover fermented brine in place of the water; leave out the salt, adding it to taste after blending. Feel free to use your Fermented Turmeric Paste instead of fresh.

1/4 cup (36 g) white mustard seed

1/4 cup (36 g) brown mustard seed

1 tablespoon (6 g) fresh turmeric root, grated or pulsed to a paste

2 teaspoons (11 g) unrefined salt

1 cup (237 ml) unchlorinated water

After Fermentation

1/4 cup (59 ml) raw apple cider vinegar

Sweetener, such as honey, to taste (optional)

1. Combine the white and brown mustard seeds, turmeric, salt, and water in a blender. Blend until the mixture reaches a paste consistency.

2. Ladle your mustard into a pint jar, pressing out any air pockets as you do. When it is all in the jar, you may need to work out any remaining pockets with a butter knife. Place the lid on the jar and tighten.

3. Set the jar on your counter and let ferment for 3 days.

4. After this curing time, open the lid (it may pop slightly as the CO2 is released) and stir in the vinegar and sweetener, if using. Your mustard is ready to serve.

5. Store the mustard in the refrigerator, where it will keep for 6 months.

Bavarian-Style Sweet

yield: about 1 1/2 cups

This mild mustard is smooth and refined yet retains a rustic heartiness. This version is not quite as sweet as its commercial counterpart; feel free to add more sugar to suit your palate. The onion mellows with fermentation and is a subtle base. Be sure to allow time for the spices to infuse in the water.

Sugar is added after the initial curing period because otherwise, the microbes will convert it to sour lactic acid. The vinegar will help ensure the sugar’s sweetness stays, but it must be added after fermentation.

1/2 teaspoon (1 g) whole cloves

1/2 teaspoon (1 g) whole allspice

1 cup (237 ml) unchlorinated water

3/8 cup (54 g) white mustard seeds

2 tablespoons (18 g) brown mustard seeds

1/2 large yellow or sweet onion, chopped

2 teaspoons (11 g) unrefined salt

After Fermentation

2 tablespoons (24 g) brown sugar or honey

1 teaspoon (5 ml) raw apple cider vinegar, or to taste

1. Place the cloves and allspice in a saucepan with the water. Bring to a boil, then remove from the heat and let cool.

2. When the water is cool, strain out the spices. Pour the spice-infused water into a blender and add the white and brown mustard seeds, onion, and salt. Blend until smooth. As the mustard seeds break down, they act as a thickening agent. The mixture will be creamy at first; keep blending until it becomes a thick paste and the onion is completely incorporated.

3. Ladle the paste into a pint jar, pressing out any air pockets as you do. When it is all in, you may need to work out any remaining air pockets with a butter knife. Place the lid on the jar and tighten.

4. Set the jar on your counter and let ferment for 3 to 4 days.

5. After this curing time, open the lid (it may pop slightly as the CO2 is released) and stir in the brown sugar and vinegar, if using. It will take a little while for the sugar crystals to melt into the mustard, at which point stir again. Now the mustard is ready to serve.

6. Store the mustard in the refrigerator, where it will keep for 6 months.

Horseradish Mustard

Makes a about 1 ½ cups

This is spicy mustard. It is a hands-down favorite at our house. If you like the spice but want a milder version, this mustard is good mixed 50/50 with mayonnaise or aioli.

Note: If you haven’t worked with fresh horseradish root you want to be aware that it can bite—as in sting your eyes and sinuses when the volatile oils are released by grating. This recipe calls for grated root; really it just needs to be small enough that it will puree in the blender with the mustard seed and water. If you have a powerful blender you can also coarsely chop the root before adding. In any case, just be cautious and don’t get your face to close to the root when working with it.

2 – 3 tablespoons fresh horseradish root, peeled and grated

2 cloves garlic, grated

1/4 cup (36 g) white mustard seed

1/4 cup (36 g) brown mustard seed

1 tablespoon (6 g) fresh turmeric root, grated or pulsed to a paste

2 teaspoons (11 g) unrefined salt

1 cup (237 ml) unchlorinated water

After Fermentation

1 tablespoon (15 ml) raw apple cider vinegar

1 teaspoon (7 g) honey

1. Place the horseradish root in the blender with the water, mustard seeds, garlic, turmeric, and salt. Blend until smooth. As the mustard seeds break down they act as a thickening agent and will become creamy. Keep blending to a paste. At this point the horseradish and garlic will also be completely incorporated into the mustard.

2. Ladle your mustard into a pint jar, pressing out any air pockets as you do. When it is all in the jar you may need to work out any remaining pockets with a butter knife.

3. Place the lid on the jar and tighten. Set on your counter to ferment for 3 days.

4. After this curing, time open the lid (it may pop slightly as the CO2 is released) and stir in the vinegar and sugar or honey. It will take a little while for the sugar crystals to melt into the mustard at which point your mustard will be ready to serve.

5. Store mustard in a jar in the refrigerator.

More resources

Recipe for Kahudi from Foodology By Kash blog. I just discovered this blog and am excited to explore it more.

Down the 🐇🕳️

Here are two papers on looking at traditional fermented mustard pastes as functional foods. Both look at mustards from the Assam region, Kahudi, and Kharoli. I haven’t had a chance to read them carefully (it is that time of year when I am making stuffed toys from old sweaters instead of nerding out on microbial studies), but I wanted to share them with you.

Selection of a multi-species starter culture for mustard seed fermentation to enhance polyunsaturated fatty acids and improve gastrointestinal health markers

Additive-induced pH determines bacterial community composition and metabolome in traditional mustard seed fermented products

This paper looks at the metabolome – which are the metabolites and small molecule chemicals found in the preparation. In many fermented foods, the metabolites produced by the fermentation is where the magic lies in the transformation of both flavor and nutritive value of the ingredient.