This is very similar to my Bourbon Barrel Stout Mustard. After drinking this beer I knew I had to make mustard from this Russian Stout. Heck I am mostly Russian by blood so why not a mustard by yours truly.
Like many of my other mustard recipes SEE HERE everything starts out with seeds and a liquid. I won't go into a lot of details here because this is so similar to my Gingerbread Stout Mustard.
Place beer and seeds in a bowl, give it a stir and place in refrigerator for 3 days. After three days place all ingredients in a food processor or in my case a vitamix. Add just enough water to help the blades process the seeds and and give it the texture you want. This is different for everyone. 
Note: there is no measurement for water. Depending on how much liquid the seeds absorbed the water content changes.
All done...
Note: In the Bourbon Barrel Beer Mustard I had use only 60 grams of Apple Cider Vinegar which created a Ph of 4.3 which was perfect for hot water bath canning. With the Russian Stout Mustard the Ph was averaging 4.68-4.72 so in order to CANN properly I added another 30 grams of Vinegar (Total of 90 grams) to bring it down to acceptable levels. For more details on how to can CLICK HERE.
