A Note on Preparing Casings
Casings are purchased packed either in a salty brine, or in moist salt. They must be rinsed inside and out, and soaked overnight before using.
To rinse the outside, place the casings in a colander under 90 degrees F (32 degrees C) running water, and rinse for 2 to 3 minutes until all traces of salt are gone. The casings may also be rinsed in a large bowl of 90 degree water, draining and replacing the water 4 or 5 times until all of the salt is gone.
To rinse the inside, place the casings in a colander in the sink. Run a stream of 90 degrees F (32 degrees C) into the sink. Find an end of one of the casings, hold it open under the running water, and fill with 8 to 10 inches of water. Gently lift the casing out of the colander, allowing the water to run all the way through to empty out the end. Repeat twice more, and set aside; do the same with the remaining casings.
After the casings have been rinsed, they must be soaked overnight, or for two hours at the very least. Place the rinsed casings into a bowl filled with 90 degrees F (32 degrees C) water, and refrigerate overnight. When you are ready to stuff the bologna, drain off the cold water and replace with fresh, 90 degree water. Allow to stand at room temperature for two hours before stuffing.