I made 3 different cured and smoked sausages a week ago. Today I pulled a link of each out of the freezer and put them on the grill until they reached an IT of 150°. As I was slicing into them I noticed that one of them was gray in color while the other 2 were the expected pink. I'm concerned that I may have left the cure out of the one that isn't pink. There was a pink smoke ring, but it was very thin. I would be pretty surprised if I left out the cure, but I am human. Is there any other explanation for the gray color? Thanks!