Where do the holes in cheese come from?
Children’s tales will tell you that they’re there because of little mice that come to nibble on the cheese at night, but the reality is a bit less fantastical.
In fact, the holes are simply carbon dioxide gas formed during the ripening of cheese. The gas is created by propionic bacteria present in the cheese who, under the effect of the wine cellar’s heat, profusely emit CO2 (more than 100L of CO2 per wheel of Emmental) which then forms the bubbles of air that you see. The higher the temperature of the maturing cellar, the more holes your cheese will have.
Note: Emmental cheese has holes but Swiss cheese doesn’t, contrary to what cartoons would have us believe.