Milk skin or lactoderm refers to a sticky film of protein that forms on top of dairy milk and foods containing dairy milk (such as hot chocolate and some soups). Milk film can be produced both through conventional boiling and by microwaving the liquid, and as such can often be observed when heating milk for use in drinks such as drinking chocolate. It is caused by the denaturation of proteins such as beta-lactoglobulin (whey protein). The thickness of the skin varies dependent on a number of factors, including the temperature of the milk, the shape of the container, and the amount of milk in the container. When milk is boiled, soluble milk proteins are denatured and then coagulate with milk's fat and form a sticky film across the top of the liquid, which then dries by evaporation. The layer does not need to be discarded and can be consumed, as protein's nutritional value is unaffected by the denaturation process. Milk film is often considered to be desirable and is used in several recipes for various foods. However, this is dependent on culture. For example, French Psychoanalyist Julia Kristeva's influential account of the abject uses the skin on milk as an important example of Horror. In various cultures Afghanistan Qaimaq Chai, or pink tea, is a traditional drink made with 2% or 3.25% milk skin. Albania In Albanian milk skin is called "mazë". It is used in various traditional dishes, the most famous of which is Flija. Flija is found all around the regions traditionally inhabited by Albanians including Kosovo, regions of North Macedonia, Serbia and Montenegro. Bangladesh Milk skin is typically known as "śōr" () in Bangladesh. It is used to make tea and milk dishes rich in taste and consistency. China Milk skin is called "nǎi pí”(奶皮) in Chinese. Considered to be of high nutritional value, Milk skin is often made into various desserts and delicacies. Milk skin is also favoured in regions such as Inner Mongolia and Tibet, as milk products are of more importance in regular diet. Double skin milk (雙皮奶) is a Cantonese dessert developed in Shunde that has milk skin on the surface. Cyprus In Cyprus, milk skin in called tsippa and is used as a filling for a pastry called tsippopitta (literally "milk-skin pie"). France In France, a type of rice pudding called teurgoule employs an extreme version of lactoderm where the milk-containing dish