Where does all the milk go?
9 hours ago
- #dairy processing
- #food science
- #global industry
- A productive dairy cow can yield about 50 liters of milk per day, which translates to roughly 43 minutes to produce a 1.5L bottle.
- Raw milk is unsafe to drink without processing due to pathogens like salmonella and E. coli, leading to widespread pasteurization for safety.
- Milk processing involves cooling, clarification, separation into skim milk and cream, standardization for fat content, pasteurization, and homogenization to prevent separation.
- From milk, diverse products are created: cream leads to butter, buttermilk, and ghee through churning and heating; milk branches into condensed milk, milk powder, yoghurt, kefir, and sour cream via evaporation and cultures.
- Cheese production is complex, involving coagulation with cultures and rennet to form curds and whey, with over 2,000 varieties worldwide based on processing methods like heating, pressing, and aging.
- Whey, a byproduct of cheesemaking, was once waste but is now processed into whey protein and lactoferrin, valued in the sports nutrition and pharmaceutical industries.
- Milk's versatility stems from being an emulsion, colloid, and solution simultaneously, allowing separation methods like centrifugation, acid addition, enzyme action, and evaporation to create multiple product streams.
- The global dairy industry is worth $800-900 billion, with New Zealand as the largest exporter, and conversion ratios show high milk usage: 10 liters for 1 kg of cheese, 21 liters for butter, and 30 liters for ghee.
- Milk proteins like casein have industrial uses in paints, glues, plastics (e.g., Galalith), and pharmaceuticals as lactose filler, extending beyond food applications.
- Humans started processing milk into cheese 8,000-10,000 years ago, predating widespread lactose tolerance, as aging reduces lactose content, making cheese digestible for lactose-intolerant adults.