Combine all Day 1 ingredients and allow to sit for 24 hours in a refrigerator. On Day 2, combine the bread and egg hold for about 30 minutes.
Soak the casings in warm water and a small amount of white vinegar until they become soft. While the casings soak, ice down all parts of a meat grinder, including a fine grinding plate and a medium grinding plate. As soon as the grinder parts are very very cold, assemble the machine.
Grind half the meat mixture through the medium plate, then add the bread mixture. Add the other half of the meat mixture until everything is ground.
Remove the medium grinding plate and replace with the fine plate. Grind all of the meat mixture again. Transfer the meat to a kitchen aide with a paddle attachment and mix until the meat is sticky. Chill the meat mixture down.
Wash and then re-chill the grinder attachments.
Thread the casings onto the sausage stuffing attachment and then push the meat mixture through until the casing begins to fill with the sausage. (This is generally a two-person job, as the meat can be very difficult to get through the machine).
Once all the meat mixture is gone, poke any air bubbles out of the hot dog using a small needle (a push pin, or safety pin will do).
Tie the hot dogs into 6" sausages.
Place the dogs into a pot and cover with cold water. Bring up to a simmer and quickly blanch them for about 5 minutes. Shock them in an ice bath and reserve for later use. At this point they can be frozen, grilled, pan fried, etc.