Great recipe, my husband and i both really like it. I have made it to give to family for the holidays this year too - i left out the allspice though, i'm just not much of a fan.
This is a nice spicy mustard, with a pleasant texture and appearance. It was very spicy when the ingredients were first combined, so I omitted the horseradish. The flavor did mellow out a bit with cooking, but it still plenty hot for my taste. I used Shiner black lager, but unfortunately wasn't able to distinguish any addition it made to the taste. I also felt uncertain about the food processor step - I wasn't able to get to a stage of "cracked" mustard seeds, only from whole seeds straight to ground mustard. My yield was about 2 cups, but I think that would be more than 6 servings!