Technical Abstract: Distillers dried grains with solubles (DDGS), the major coproduct from the corn-based fuel ethanol industry, is primarily used as livestock feed. Due to high protein, fiber, and energy contents, there is a high demand for DDGS. Flowability of DDGS is often hindered due the phenomenon of ¿caking¿. Shipping and handling of DDGS has thus become a major issue due to bridge formation between the DDGS particles. The objective of this investigation was to measure flowability characteristics of DDGS samples from five ethanol plants in the north central region of the U.S. Carr and Jenike tests were performed, and the resulting data were mathematically analyzed using a previously developed empirical model. These results will be presented and discussed. Quantifying DDGS flowability is a necessary step toward overcoming this logistical challenge facing the fuel ethanol industry.