For enthusiasts, making sausages at home offers the opportunity to have exactly the flavor and texture you want. All that's required is a meat grinder, a sausage stuffer, and some patience. You can usually buy casings in small quantities from a friendly butcher or in larger packages online. Natural casings are usually sold in buckets of light brine, and they're finicky and prone to spoilage. Edible collagen casings are sold in dry, shelf-stable form, so they're better for hobbyists.
Select a "stick" of collagen casing and examine it for damage. If it has any visible cracks or breaks, cut those sections away.
Slide a section of collagen casing over the filling tube of your sausage stuffer, pushing it back as far as it will go. When the filling tube is completely covered, snip off the remaining length of casing. Twist the cut end around your finger and tie the twisted section into a knot.
Fill the hopper of your sausage stuffer with the chilled sausage mixture. Hold the beginning of your casing, where it's tied, lightly but firmly between your thumb and forefingers. Start the sausage stuffer.
Hold the casing in place as the meat mixture begins to emerge from the filling tube. Once the end of the casing is filled, relax your grip slightly and let the pressure of the emerging sausage slide the casing from the filling tube. Maintain enough pressure that the casing fills completely, as it slides from the sausage stuffer.
Continue filling the casing until you either run out of sausage mixture or come to the end of your casing. Tie off the end of your casing as you did at the beginning and snip it if you have casing left over. If you still have filling left, slide a new piece of casing onto the sausage stuffer and repeat until you run out of sausage mixture.
Twist the sausages into links, if you wish, by giving each section four or five gentle turns. Tying them with string will help keep the links from unrolling, as you continue down the length of your sausage.
Look for bubbles where air is trapped between your sausage and the casing. Pierce those with a toothpick or sterilized straight pin to minimize the risk of spoilage.