I have tried to make mustard with the thermomix using mustard seeds, and this is the problem.
If you heat mustard seeds they go somehow bitter and lose a lot of the heat.
This is what i tried since then.. It is a great recipe to make grainy mustard but you can not make it in an instant, it needs some time to rest and to develop. You use mustard seeds and soak them in a mix of vinegar and water. The water makes them want to sprout and the vinegar slows the process down.
This is how i go:
250 grams dark mustard seeds
250 grams yellow mustard seeds
250 mll water
250 mll of white vinegar
100 mll of white wine vinegar
About 2 teaspoons of salt
Put all of the ingredients in a glas jar and shake.. Let it rest for several days and shake now and then.
The grains will swallow and soak up the liquid. If tondry add some more water or vinegar - yhe mire vinegar the stronger the mustard will be.
After a week (better after a few weeks) put everything in the thermomix and blend to the wanted consistency...
Beware this whill not give you a smooth dyon, but a grainy mustard. If you like more seeds then blend for a shorter time, if you want a smoother mustard then blend for a longer time at high speed.
If you want a more dyon style mustard, you can stard with ground mustard powder .. Let the mixture rest for two,days and blend. Add water and/or vinegar untill the right consistency is reached. Be aware that you may have to add liquid kater, because even the powder keeps swelling and absorbing liquid as you go.. You can keep the mustard for months, but it will not last that long for sure.
The thing is a bit experimenting with the wet ingredients.. Some grains are drier the other and you may add liquid several times.
If you want a more yellow mustard add a bit of curcuma powder.
and keep us posted