Yes, you can ferment mustard. I’m not sure why it isn’t more of a thing. In the same way that Dr. Andrew Weil called vinegar pickles “dead pickles,” (fermented pickles being living pickles, of course), we can say that the normal store-brand mustard is “dead.” Tasty, sure. But from a probiotic perspective, dead.
Fermented mustard doesn’t just offer the usual health benefits of mustard, such as improvements to metabolism and digestion, lowering blood pressure, inhibiting cancer cells’ growth, and more. The fermentation process allows the healthy bacteria present on mustard seeds (as well as the other produce added) to proliferate and enter your gut microbiome, offering additional healthy enzymes and further helping to improve digestion and overall gut health.
Like just about all other ferments, it also adds a distinct flavor.
I’m going to provide a flavorful recipe and give the details for a couple ways I finished it up when blending (one with added lacto-fermented horseradish and one with added honey fermented garlic; these added ingredients are not required for this delicious mustard, just options).
Also, I like my mustard smooth and creamy and therefore added vinegar after fermentation and blended it vigorously. Don’t worry, adding vinegar after a ferment does not actually kill probiotics, though it can reduce the pH to the extent that the probiotic bacteria will no longer reproduce… and it’s worth noting that the bacteria eventually does this to itself over the course of fermentation anyway.
Also, as an alternative to blending to a smooth paste, you could opt for a whole grain or coarsely ground mustard if you prefer those styles. (But then you’d need to separately blend the other components… the garlic, ginger, yellow pepper, etc.)
Shelf life: Like other fermented foods kept in refrigeration, this mustard can potentially last for years. The addition of vinegar at processing will further ensure shelf life.
This recipe yields about two quarts (a half gallon) of mustard.
You will need:
- Half gallon jar with a fermentation lid
- Measuring cups and spoons
- Knife & cutting board
- Suggested: ferment weight suitable for half gallon jar
- 2.5 cups mustard seeds (I typically use 1.25 cups yellow & 1.25 brown; using a 50/50 ratio is popular but more brown will make a hotter mustard)
- 4 cups filtered or distilled water
- 2 TBSP additive-free salt
- 150g pineapple (fresh, canned or frozen)
- 10-15 cloves garlic (or a full head) (~40g), quartered
- ~40g ginger, thin-sliced
- 1/2 large yellow bell pepper, seeded & cored
- Hot peppers as desired (I added a couple orange habaneros and a bit of ghost pepper; if you want a very spicy mustard I recommend more)
After the ferment:
- Up to 2 cups white wine vinegar at blending, or to desired taste & consistency (may substitute fully or partly with white vinegar, apple cider vinegar, or other clear/light-colored vinegar).
- 1 tsp salt per each cup of vinegar
- To increase mustard heat: 1-2 TBSP of pure ground mustard powder, yellow or brown, at the final blending.
- For a true spicy mustard: add 1-2 TBSP cayenne powder at the final blending.
- Optional: consider adding other fermented items at blending; for example, 1/2 cup fermented horseradish or honey fermented garlic
- Optional: instead of adding those fermented items, for a sweet or honey mustard, you can add sugar or honey (blend in a TBSP at a time to taste). Honey fermented garlic is not very sweet after it has aged but you could also consider mixing it together with fresh honey or other sweetener.
1.) Add all the mustard seeds and prepared produce to the jar, placing the seeds in first. Add increasingly larger components, ending with the pepper half. Use the pepper half as a covering so as to prevent any floaters.
2.) Prepare the brine by mixing the water and salt in a sealed container and shaking it vigorously. (Or combine warm water with salt and allow to cool.)
3.) Once the pepper half is securely holding everything down (and/or using a fermentation weight), gently pour the brine over to prevent dislodging the mustard seeds & pausing periodically to allow time for the water to seep down. Use all the brine and be aware that over the next few days, the mustard seeds will absorb much of the brine and they will swell quite a bit. (The recipe includes enough brine to account for this and still allow for all veggies to be submerged.)
4.) All veggies including the pepper should be submerged. As an added precaution, adding a fermentation weight on top of the pepper is advised. Then apply the fermentation airlock (or use the burp method) and allow at least one month at room temperature to ferment (longer is fine).
5.) At the end of the allotted time, strain out any excess brine (if present) and blend all solids until you reach the desired consistency.
6.) Add up to two cups of white wine vinegar and other additions for the final blending (this will also make the mustard suitable for a squeeze bottle).
For this mustard, I add around 1.75 cups white wine vinegar but it can also be a mix of vinegar and any reserved ferment brine, and blend for 5-10 minutes on high, to achieve the desired consistency. For each cup of liquid added, you can add up to 1 tsp of salt if you want to maintain the level of saltiness. See the ingredients list above for ideas of what to add at blending.
You’re recommended to place and keep the jar in a larger bowl, as the seeds will roughly double in size. Although they’re absorbing brine, you may find that everything in the jar gets pushed upwards, so a glass weight is a good addition if you can fit it. Otherwise, the yellow pepper should be cut large enough to remain firmly in place.
For the batch of mustard featured in this post, I made half with added fermented horseradish (about 1/4 cup), and one with added honey fermented garlic (1/3 cup). Note that these quantities were for half the mustard; you could double the amount (to a 1/2 cup) if it’s to blend into the entire batch of mustard.
Alternately, you could consider dividing into several small variations from your main batch as well. FYI, the featured photo of this post is the horseradish mustard.
I always add the cayenne or other dried hot pepper at the final blending (mentioned in the ingredients section) to round out the flavor.
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