RE: Sport Peppers - What are they?
Michael, I don't believe they are serranos. I mail order Il Primo HOT Sport peppers by the case as pictured above courtesy of Mar 52. Looking at an unopened jar at the moment, the label reads "HOT Sport Peppers", Mar's label reads "Chicago Hot Dog Sport Peppers". I choose fresh serranos over jalapenos at the grocery store. Even though my Sports are called "hot", the Scoville unit level is much lower than Serranos. They have a slight but distinctive shape difference compared to a serrano. My experience......Both are from the pepper family but cousins in my opinion. Sports are a variety as is Serranos.
Ingredients listed on this jar are listed as follows: sport peppers, vinegar, salt, FD&C, yellow 5. They are described as "Mississippi style sport peppers made famous by Chicago style hot dogs. Used for decades in beef, hot dogs, and pizza establishments all over Chicago". Hope this helps.