Machines for popping corn and producing puffed snacks and other expanded foods are described herein. In one embodiment, a flow-through popper circulates unpopped corn kernels through a popping chamber by use of a plurality of vanes that directionally control a flow of high velocity, high temperature and high pressure air. In this embodiment, the air in the popping chamber causes the unpopped corn kernels to circulate as they move through the length of the popping chamber without the need for an auger or other moving apparatus.