Why we don’t make cheese from mummy’s breast-milk

Cheese-making is a prehistoric craft. Cheese is usually made from animal milk, from cows, goats or sheep. Archaeological evidence suggests that milk production is likely to be as old as the domestication of sheep. Secure evidence in the form of milk fat residues in strainers and pots dates as early as 5500 BC in Poland (Salque et al. 2013). Preserved cheese from the Taklamakan Desert in Xinjiang , China, dates to 1615 BC. Egyptians, Greeks and Romans, as well as people of the European Iron Age produced cheese. Swiss cheese flavours may go back to the first Millennium BC.

Making cheese preserves a valuable foodstuff for a longer time period. So is it at all possible that prehistoric people made cheese from human breast-milk?

To make hard cheese, milk is usually acidified and adding rennet causes coagulation, separating solid curds for and liquid whey. The solids are separated and pressed into final form. Rennet is found in the stomachs of young animals that still digest milk as their primary food source. Rennet used for modern cheese making is a by-product of slaughtering veal and lamb. In prehistory, its function was likely discovered by chance when milk was stored in animal stomachs.

The traditional way of making rennet is slicing dried and cleaned stomachs of young animals and putting them in water or whey, together with some vinegar or wine, for a few days. The filtered solution can be used to coagulate milk. A little goes a long way with this process – 1 g of this solution can coagulate 2 to 4 l of milk.

What I did not know before developing an unhealthy level of theoretical interest in cheese-making is that the enzymes found in the animal stomachs are specific to the species. To make cheese, you have to add rennet from the stomach lining of the animal you are making the cheese from: to make cheese from cow’s milk, use rennet from calves, to make sheep cheese, from lambs. To make cheese from human breast-milk, you would need the stomach lining of…. you get it. Nobody would do this (but some have thought about it).

Thank goodness, there are alternatives to rennet today. The key component of rennet is the enzyme chymosin, which may be obtained from genetically modified bacteria, fungi or yeasts by fermentation. Yay for genetic engineering! To the best of my knowledge, nobody has engineered a suitable agent for human breast-milk yet.

Cream cheeses and other soft cheese alternatives are made by coagulating milk with acid. So if you are really desperate, try this method. Alternatively, mix human milk with cow’s milk, like in this recipe from New York chef Daniel Angerer.

Reference

Salque, M., P. I. Bogucki, J. Pyzel, I. Sobkowiak-Tabaka, R. Grygiel, M. Szmyt, and R. P. Evershed. 2013. Earliest evidence for cheese making in the sixth millennium bc in northern Europe. Nature 493(7433): 522-525.