Rennet

As such, those chemicals are occasionally added to supplement pre-existing quantities in the cheese making process, especially in calcium phosphate-poor goat milk.

[citation needed] Calf rennet is extracted from the inner mucosa of the fourth stomach chamber (the abomasum) of young, nursing calves as part of livestock butchering.

[3] Rennet extracted from older calves (grass-fed or grain-fed) contains less or no chymosin, but a high level of pepsin and can only be used for special types of milk and cheeses.

[4] Dried and cleaned stomachs of young calves are sliced into small pieces and then put into salt water or whey, together with some vinegar or wine to lower the pH of the solution.

[citation needed] One kilogram of rennet extract has about 0.7 g of active enzymes – the rest is water and salt and sometimes sodium benzoate (E211), 0.5%–1.0% for preservation.

[6][7] Because of the limited availability of mammalian stomachs for rennet production, cheese makers have sought other ways to coagulate milk since at least Roman times.

[10] Other examples include several species of Galium, dried caper leaves,[11] nettles, thistles, mallow, Withania coagulans (also known as Paneer Booti, Ashwagandh and the Indian Cheesemaker), and ground ivy.

], microbial coagulants have improved greatly, largely due to the characterization and purification of secondary enzymes responsible for bitter peptide formation/non-specific proteolytic breakdown in cheese aged for long periods.

With genetic engineering it became possible to isolate rennet genes from animals and introduce them into certain bacteria, fungi, or yeasts to make them produce recombinant chymosin during fermentation.

[16] Originally created by biotechnology company Pfizer, FPC was the first artificially-produced enzyme to be registered and allowed by the US Food and Drug Administration.

FPC provides several benefits to the cheese producer compared with animal or microbial rennet: higher production yield, better curd texture, and reduced bitterness.

[16] Cheeses produced with FPC can be certified kosher[24][25] and halal,[25] and are suitable for vegetarians if no animal-based alimentation was used during the chymosin production in the fermenter.

[26][27][28][29] In Yazidism, the Earth is believed to have coagulated and formed when rennet flowed from the White Spring of the celestial Lalish in heaven into the Primeval Ocean.