Sausage casings hold the meat together but they also serve another important function in retaining the meat's moisture. Prodding the casing causes all the fats and juices in the meat to seep out ...
I don’t typically end up eating the casings anyway, so I prefer to make sausage in bulk. Packing it into vacuum bags one pound at a time makes it easy to store in your freezer, quick to defrost ...
I only use a fine grind when I specifically want that result (which is almost never!). Place the twice-ground brat mixture in the fridge while you set up your meat grinder for stuffing sausage links.
Rinse under very cold water well. Feed casing over the sausage stuffer attachment of your grinder. Twist the end of the casing. Load ground meat in the hopper. Fill the casings pretty full.