In the past, Bottle Caps contained a lemon-lime flavor instead of the current cherry flavor. There was also a time when Willy Wonka Co. made Fizzy Bottle Caps (called Fizzy Jerkz in the UK). These were a little bit like the original but contained ingredients to make them fizz when eaten, making them a bit more flavorful.
In early 2009, each individual piece of Bottle Caps candy was made much smaller than they had been in the past. The underside was flattened, and no longer resembles the underside of a bottle cap. The paper tube packaging retains the original size and shape.