Jace's Famous Brat-Burgers
12 lbs. lean ground beef (round would be ideal, I usually use the shop trim, which is somewhere in the mid to upper 80% lean realm).
10-12 lbs fatty ground pork (two boned pork shoulders are about perfect. I usually trim the top cap off first and use for salt pork since we don't want these burgers swimming in grease)
16oz Bratwurst seasoning (I mix my own, but you can find them available for sale. Look for a mixture whose first ingredient isn't salt and lists Mace amongst the top 5 ingredients)
2 Cups beer.
Mix very well, but don't over mix. One trick is to mix the meats together first, until it's about the texture of meat loaf, then roll out the meat and evenly distribute the spices. (Thanks Alton Brown). Then fold up and mix the mixture with the beer until you get an even distribution of spices and a slightly sticky texture. You can make patties any way you wish, but usually the mixture is too sticky to use the traditional patty makers. I like to just roll up the meat into 3# logs, wrap them in butcher paper and freeze over night. Then I cut the patties out on the band saw with a bone-in blade.
Grill them just on the far side of medium (because of the pork) and top with either brown mustard and kraut, or lettuce, tomato, onion and Mayo. Garlic Aioli would be awesome, too.