Earlier this week, I shot a video on grilling for a new digital magazine being created by Sideways. I did a spatchcocked chicken, grilled asparagus and also sausage, because, after the infrenal boneless skinless chicken breast, it's the most overcooked meat in America, and yet it's rightly beloved here.
In my experience people err because they're afraid of not cooking it enough. So they either cook it over really high heat, overcooking the outside, busting open the sausage, or they kill it with too much moderate heat.
As we move into grilling season, and there's no better way to cook a sausage than over the smoky heat of live coals, I encourage you to grill sausages often. All carnivores around you will be happier.
There are two stages to grilling a sausage to perfection. Start it over moderate direct heat to give it flavor and color. Finish it in a covered grill over indirect heat till it's reached the appropriate internal temperature. Pork sausages should be grilled to 150 degrees F./65 degrees C. Poultry sausage should be cooked to 160 degrees F./70 degrees C. The above sausage is my favorite all-time sausage, chicken with basil tomato and garlic, from Charcuterie, bien sur. As you can see I went a little over on this one! (A few degrees are ok if the sausage is any good.)
So, stop overcooking your sausages! The casing should crack! when you bite down and juices should explode in the mouth.
[About thermometers: I used this Maverick thermometer, available at Open Sky (the company sent it to me to test when Open Sky couldn't source the comparable Thermopen; it's very good, can be used for candy and deep-frying; it tested well for both speed and accuracy; when I told Mike at Open Sky I was posting on sausages, he created a coupon so that we could sell this for less than Amazon does—use the code "Maverick15" at checkout for a 15% discount). You can also use this inexpensive Taylor instant read, works perfectly fine for sausages. Want to grill them tonight? Most hardware stores carry decent instant read thermometers. The point is, own a thermometer, and use it to know exactly when your sausage is done.]