Thermoduric describes bacteria that survive pasteurisation — from the Greek therme, heat, and the Latin durus, hardy. These organisms, which include certain Micrococcus, Enterococcus, and spore-forming Bacillus species, endure the standard 72°C for 15 seconds that kills pathogens, not because they are dangerous but because they are tough. They matter to the dairy industry because they persist in pasteurised milk and on equipment, where they can cause spoilage, off-flavours, and reduced shelf life, and their presence can indicate inadequate cleaning. Thermoduric does not mean thermophilic: these bacteria do not love heat, they merely withstand a brief exposure to it. Controlling them depends on hygiene at the farm and in the plant.