Being the new guy to sausage, after a few batches here's what I learned.
1. Butts average about 70/30 perfect for my sausage. Only once have I needed additional fat. I now usually just cut my extra fat up for cracklins.
2. I smoke by color, I have learned using a poaching device allows me better heat control to cook. (I use a roaster now).
3. I cook sausage to 153 degrees, then I dump 'em in a pan of ice water. It keeps the wrinkles from forming, AND it seems to make the skins less tuff. Yes it does dilute the smoke flavor, but if its too much you can smoke it again. I have not had the need yet, although I did try it on a couple a batches. This not only maintains a plump sausage but a juicy one as well.
4. Depending upon the type sausage I have learned to like a binder, be it powdered milk or a phosphate, or both.
5. I smoke my sausage never exceeding around 130 smoker temp. I do NOT render that way.
I am still experimenting and learning from the guys around here. I now make sausage and andouille that I like. Thats why I started in the first place. Not counting my time, my product costs approx. 1.50/lb for what I pay 6 to 7.50/lb for from the market (and mine is better!).
Now since I got bug bit, am wanting to start trying sausages I have eatten before mut only once or twice, and I want to ferment! I gotta learn to make thuringer!
Ok, there is nothing wrong with those sausages, lots of sausages sold here are wrinkled. Most of the best ones are.