This one surprises people. Fresh sausage has a natural, savory, meaty smell—maybe a hint of garlic or herbs. Bad sausage, on the other hand, can suddenly smell sickly sweet, like rotting fruit or old honey.
I once made the mistake of thinking a “sweet” smell meant it was honey-cured. It was not honey-cured. It was bacteria-cured, which is not a thing. If your sausage smells like a candy store that also has a leaky garbage bin, run.
The Yeasty Bread Trap
Another weird one is a yeasty, bready smell. Perhaps you open the package and think, “Huh, that reminds me of rising dough.” That is not a compliment.
Spoiled Sausage Amazon.com: Vincent's Meat Market Hot Italian Sausage
Fresh sausage doesn’t smell like a bakery. It smells like meat. If you get a whiff of sourdough or beer gone flat, your sausage is hosting a party for microbes. They are not friends. Kick them out—into the trash.