I use venison and pork here, but beef and pork or all pork work well, too. Juniper berries are important to the flavor of this sausage, and you can either gather them (see above) or buy them. Some big supermarkets carry them, and you can always buy juniper berries online.
Chop venison and pork fat into chunks that will fit into your grinder. (Expert step: Mix the salt and curing salt with just the meat and refrigerate overnight. This helps develop myosin, which helps bind the sausage better later.)
Take out about 10 feet of hog casings and set in a bowl of warm water to rehydrate. If you haven't already done so, combine the salt, curing salt, herbs and spices with the meat, mix well. Chill the meat and fat until it is almost frozen by putting it in the freezer for an hour or two.
Grind through your meat grinder using the coarse die; I use an 8 mm or a 10 mm die for this. If your room is warmer than 69°F, set the bowl for the ground meat into another bowl of ice to keep it cold. Put the mixture into the freezer while you clean the grinder, then submerge the auger, die and blade into ice water to chill it down. Now grind a second time through the fine die; I use a 4.5 mm for this.
Return the mixture to the freezer until it is very cold, about 32°F. When it has chilled sufficiently, add the gin and cold water and mix thoroughly either using a Kitchenaid on low for 60 to 90 seconds or with your (very clean) hands; I use my hands, which should ache with cold as you do this.
Stuff the sausage into the casings. Twist off links by pinching a link and twisting it, first in one direction, and then, with the next link, the other direction. Or you could tie them off with kitchen string. (This video shows how I do it.) When they are all made, gently compress the meat in the links with your hands, then spin them in the direction you used to make the link in the first place to tighten. This will reveal air pockets. Use a clean needle to pierce the casing to remove them.
Hang the sausages in a cool place. In a normal room, hang for 2 hours. But if you have a place where the temperatures are between 33°F and 40°F, hang up to overnight. Once the links have dried a bit, put them in the fridge until needed. They will keep for at least a week.
Notes
This recipe makes about 5 pounds of sausage.
Options and Keys to Success
You only need the Instacure if you plan on smoking your sausages. Smoke to an internal temperature of 150°F over the course of a few hours. Wood choice is up to you. When they are done, plunge the links into a basin of ice water to stop the cooking process. Chill, dry and freeze.
You can skip the juniper if you really want to. Ditto for the gin. Just leave the juniper out, or replace it with rosemary or young spruce tips. Replace the gin with ice water.
You don't have to case this sausage. You can make patties, too. It is not strictly speaking an American breakfast sausage, but it can serve that role.