B. coagulans is a gram-positive rod (0.9 by 3.0 to 5.0 μm in size), catalase positive, spore-forming, motile, and a facultative organism. it's going to seem gram-negative once getting into the stationary part of growth. The optimum temperature for growth is fifty °C (122 °F); range of temperatures tolerated are 30–55 °C (86–131 °F). IMViC tests VP and methyl-red tests are positive.