Emmentaler is a yellow, medium-hard cheese, with characteristic large holes. It has a piquant, but not really sharp taste. Three types of bacteria are used in the production of Emmentaler, Streptococcus thermophilis, Lactobacillus, and Propionibacter shermani. In the late stage of cheese production, P. shermani consumes the lactic acid excreted by the other bacteria, and releases carbon dioxide gas, which slowly forms the bubbles that make holes.