A method of dosing a popping chamber with a predetermined quantity of bulk starch material comprises placing bulk material into a feed hopper, positioning a dosing plate and a shuttle plate into a charging position relative to the seal plate, and positioning the dosing plate and the shuttle plate into a dosing position relative to the popping chamber and to the seal plate. The dosing position is characterized by alignment of the dosing apertures and the shuttle apertures and misalignment of the seal plate apertures and the dosing apertures such that the bulk material retained in the dosing apertures in the charging position flows through the dosing apertures and the shuttle apertures into the popping chamber in the dosing position and bulk material is not flowable through the seal plate apertures into the dosing apertures in the dosing position.
