So I'm going to make some beef and pork sausage. The beef I have is lean. I would like it to be juicy when cooked. What's the cut of pork to use? I will grind it myself. I'm going to do 60% beef 40% pork. Any info would be great thanks.
Pork butt (shoulder roast) is mostly used for sausage due to its high fat content. Since you have 60% lean beef, adding extra fat from the fat cap of the pork will also help.
For a good sausage I work to a ratio of around 80:20 meat : fat which can be adjusted according to taste. A mix of pork shoulder and pork belly (2:1 or 1:1) may be used but after making sausage for a number of years I have settled on pork collar (pork neck in some countries?) and pork belly in a 2:1 or 1:1 ratio depending on the sausage I am making.
Typically I grind meat for sausages twice but have found that a single grind produces a really nice coarse mix ideal for some sausages such as a fennel Sicilian pork sausage. :)
As a caveat if you are mixing lean beef and pork 60:40 as a ballpark figure pork shoulder/collar is around 15-20% fat and belly 30-35% fat therefore you will need to adjust the pork fat content so the end product is around 80% meat 20% fat, sometimes a bit of trial and error is required particularly as you want a juicy end product but that is part of the fun! :)
The fat content figures is for UK pork, not sure if US or Canadian pork differs? It is always worth talking to your butcher if you get a chance! ;)