Homemade Whole Grain Mustard Magic
Feb 20,2025
Feb 20,2025
Some foods taste much better when you make them yourself, though you buy them at the store without a second thought. A case in point is homemade whole-grain mustard, a favorite of Tanaka Kanako, an expert in oil-free cooking. It’s a cinch to prepare a batch to keep in the fridge.
Here Kanako tells us how to concoct this tasty condiment. She also shares her recipe for an oil-free marinade made with it — one that goes perfectly with a fresh, juicy plate of slightly bitter-tasting spring vegetables. Further, we ask her about ama-koji (sweet rice malt), a fermented food essential to making oil-free dishes taste delicious.
Kanako often prepares her own whole-grain mustard. “When I found out you could make it yourself, I gave it a shot, and I was amazed at how easy it was — and how good it tasted.” All you do is let mustard seeds soak for a while in a rice-vinegar-based liquid seasoning. Then you crush the seeds to your desired coarseness and let the flavor sink in. And that’s it.
The great thing about homemade is that you can make it taste how you like.
“Two types of mustard seeds, the source of the pungent taste, are used: yellow and brown. Brown seeds are hotter and more bitter, and you can adjust the hotness by varying the percentage of each. I use rice vinegar because I prefer a smooth, acidic taste, but you can substitute cider vinegar or white wine vinegar if you like. You can also flavor the mustard with spices and herbs. It’s nice to be able to tweak it as you like.”
Some people can’t think of any way to use whole-grain mustard but as a garnish for sausages, so they end up having more of it than they know what to do with. But it can be used for much, much more, says Kanako.
“With its mildly acidic flavor and moderate pungency, it’s the perfect garnish for steak, roast beef, and pot-au-feu. Or you can mix it with whipping cream and heat for a no-fuss sauce to jazz up meat or fish. It also nicely plays up the sweetness and umami of vegetables. And it makes a tasty garnish or dressing for tender, fresh, slightly bitter spring vegetables, which will soon be on the shelves.”
Kanako’s homemade whole-grain mustard. Consistency and mouthfeel vary depending on how finely crushed the seeds are.
*Or substitute your favorite vinegar or wine vinegar.
Prepare a total of 30 g of yellow and brown mustard seeds. “The recipe calls for two parts yellow seeds to one part brown. For a sharp kick like Japanese mustard, use them in a one-to-one ratio instead. Feel free to use sugar in place of honey.”
1.Place the mustard seeds in a jar sterilized in boiling water. Combine the liquid seasoning ingredients and pour over the seeds.
All you do is pour on a liquid seasoning made with simple ingredients: rice vinegar, honey, and salt.
2.Screw the lid on loosely and let sit at room temperature for about three days. During that time, once the mustard seeds absorb all the liquid and there’s no moisture left, add just enough extra vinegar to cover them.
Left: Immediately after being soaked. Right: Three days later. The mustard seeds swell up as they absorb the liquid. They absorb a considerable amount of vinegar in the first three or four hours, so keep an eye on them and add extra vinegar as needed.
3.Pour the mustard seeds into a bowl and crush to your desired coarseness with the back of a spoon or something.
Crush the seeds to your desired coarseness and consistency. “I just give them all a quick once-over. It’s faster to do the job in the food processer, but be careful not to crush the seeds too much.”
“You can eat the mustard as soon as it’s made, but it tastes even better after being left for a while. It assumes a milder, mellower flavor as the bitterness and pungency blend in.”
Kanako also shared her recipe for an oil-free marinade prepared with homemade whole-grain mustard. It’s a great way to eat plenty of spring vegetables.
Marinades are generally thought of as being made with oil. But as Kanako explains, “This marinade tastes good even without the oil. The whole-grain mustard accentuates the flavor, and adding ama-koji (sweet rice malt) gives it extra richness. It has a nice, refreshing taste.”
For this feature, Kanako prepared a marinated dish of tender, delicious spring turnips with smoked salmon. “You can substitute snap peas or broad beans for turnips. I like using this marinade to make the sort of marinated dish you might eat with a bowl of rice, combining freshly harvested onions, tomatoes, celery, and squid. I also enjoy using it to marinate thin strips of carrot à la carotte râpé or shredded and microwaved cabbage à la sauerkraut.”
Peel 200 g of turnips, slice into thin quarter circles , and salt to soften. Lightly rinse and drain. Slice 80 g of smoked salmon into 3–4 equal pieces. Let the turnips and salmon sit in a marinade made with 2 tbsp. each of white wine vinegar and ama-koji, 1 tbsp. whole-grain mustard, a touch of honey, and salt and pepper to taste. Cut a lime (or lemon, yuzu, or other citrus) into slices and mix in.
“When coming up with recipes for oil-free dishes, you need to get creative about substituting other ingredients for oil,” says Kanako. “What I often use instead is ama-koji.”
Ama-koji is a condensed form of the fermented rice beverage amazake. Kanako makes it by fermenting koji rice malt, rice, and water. “It tenderizes fish and cuts of meat like chicken breast by breaking down proteins through the action of enzymes. When added as a flavoring as in the oil-free marinade I’ve just shared, it gives food extra richness, so the taste is satisfying even without oil.”
Kanako takes advantage of ama-koji’s sweet taste by using as a substitute for sugar and mirin cooking sake as well. “It’s easiest to use a yogurt maker, but it can be made in a rice cooker as well.”
Here’s how to prepare ama-koji at home. Make a slightly firm rice porridge with 100 g of rice. Cool to 50˚C by adding 50 ml of cold water. Break up 100 g of dried rice koji and add to the porridge. Maintain at a temperature of 55–60˚C for 8 hours. “Leaving ama-koji in the fridge for four or five days before using makes it sweeter and enhances the sour taste from the lactic acid bacteria.” It keeps in the fridge for about 20 days.
Kanako also shared her recipe for ama-koji dressing — a simple way to experience the great taste of oil-free foods made with ama-koji. This dressing can be made in a jiffy: just add vinegar and salt to ama-koji and mix together. Its smooth, mellow flavor goes with just about anything. That’s part of its beauty.
“The thing about it is, it isn’t just full-flavored. It has a naturally thick consistency. It’s like an oil that’s been emulsified to thicken it. It clings beautifully to the salad ingredients.”
Mix together 2 tbsp. ama-koji, 1 tbsp. white wine vinegar, and ½ tsp. salt.
Culinary expert, international medicinal chef, and food coordinator
Culinary expert, international medicinal chef, and food coordinator
Tanaka Kanako runs a cooking school out of her home. She’s been exploring non-oil dishes that anyone can enjoy since a member of her own family developed a health condition. She is the author of Rice Flour Muffins Made with Oil-free, Gluten-free Dough: Enjoy Them for a Snack or a Meal and Rice Flour Chiffon Cake: Oil-free, Gluten-free, and Gentle on the Body (both published by Shufu no Tomo Sha), and Stress-free Meals for Crohn’s Disease and Ulcerative Colitis (published by Kagawa Nutrition University Publishing Division).
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