There are many different types of cheese, which can be grouped or classified according to criteria such as: length of fermentation, texture, production method, fat content, animal source of the milk, and country or region of origin. These criteria may be used either singly or in combination,[1] with no method used universally.[2] The most common traditional categorization is based on moisture content, which is then further narrowed down by fat content and curing or ripening methods.[3][4]
The combination of types produces around 51 different varieties recognized by the International Dairy Federation,[3] over 400 identified by Walter and Hargrove, over 500 by Burkhalter, and over 1,000 by Sandine and Elliker.[5] Some attempts have been made to rationalise the classification of cheese; a scheme was proposed by Pieter Walstra that uses the primary and secondary starter combined with moisture content, and Walter and Hargrove suggested classifying by production methods. This last scheme results in 18 types, which are then further grouped by moisture content.[3]