A generic cheese common to many countries for several related varieties of cheese which resemble the Swiss Emmental. Three types of bacteria are used in the production of Emmental cheese: Streptococcus salivarius subsp. thermophilus, Lactobacillus (L. helveticus or Lactobacillus delbrueckii subsp. bulgaricus), and Propionibacter (P. freudenreichii or P. shermani). In a late stage of cheese production, the Propionibacter consumes the lactic acid excreted by the other bacteria, and releases carbon dioxide gas, which slowly forms the bubbles that develop the eyes. Swiss cheese without eyes is known as "blind."