put mustard seeds and beer in a non-reactive bowl and let stand overnight.
pour into a food processor and pulse several time to break up the seeds. then run the processor until the seeds are ground up to the size you prefer(the bigger the seed pieces, the greater the heat).
add the rest of the ingredients to the food processor and blend completely, please note, this should be thicker than yellow mustaed, but not much. Store in a squeeze bottle in the refirgerator. Enjoy with grilled brats (family favorite).