A heated air popcorn popper and related methods of popping popcorn in which unpopped kernels are retained in a heating zone and are prevented from being expelled before they have been exposed to a heated air stream for sufficient time to result in popping of the kernels. The popcorn popper can have a popping portion including a retention mechanism capable of moving in response to physical contact with popped kernels that experience a dramatic volumetric increase in size following popping. As the number of popped kernels within the popping portion increases, the level of the popped kernels rises until they physically contact the retention mechanism, whereby the retention mechanism is forced to transition from a covering disposition to an open disposition in which popped kernels are allowed to exit the heating zone.
