Mesophilic
Describes starter bacteria that work best at moderate temperatures, used for cheddar, Gouda and soft cheeses.
Also: mesophilic culture, mesophile
Mesophilic, from Greek words for middle and loving, describes bacteria that grow best between about twenty and thirty-five degrees. Mesophilic starter cultures, mostly Lactococcus and Leuconostoc species, are used for cheeses whose curd is not heated above roughly forty degrees: cheddar, Gouda, Edam, Camembert, Brie, most blue cheeses and most fresh cheeses. Some strains also make gas, giving the small eyes of Gouda and the open texture of blue cheeses. Too much heat kills or slows them, which is why cheeses cooked hot, such as Parmigiano and Comté, use thermophilic cultures instead. Many cheeses use a mix of both kinds.