A method of preparing a shelf-stable processed grain product includes a series of heating and cooling steps performed on a processed grain product having a water activity value of about 0.65 or less. A first heating step takes the grain pieces to a first elevated temperature, which is followed by a first cooling step. The grain pieces are passed to a second heating step to reach a second elevated temperature, followed by a second cooling step. The grain pieces are then passed to a third heating step, after which they are sufficiently soft and pliable for a final forming step such as flaking, bumping, puffing, or the like. This allows grain pieces that are suitable for long term storage, but too brittle for final forming, to be softened for final forming without raising the moisture content to a point that is conducive to mold formation or reduced product quality.
