Why does milk spoil?
The short answers is that milk is a natural food with naturally-occurring bacteria and prolonged exposure to heat, air, direct sunlight and other potentially damaging elements can cause milk to spoil (just like any other food). The longer, more scientific answer is that prolonged exposure to potentially damaging elements can cause the naturally-occurring bacteria in milk to multiply. This in turn, causes the lactose in the milk to convert into glucose and galactose, which causes lactic acid to be produced. Lactic acid creates casein, which causes clumps or curds to form...aka "spoiled".
How can I tell if the milk is spoiled?
Simple! To determine if milk is spoiled, you can look at, smell and taste it! When spoiled, milk will look spoiled (curdled), smell spoiled (sour) and taste spoiled (sour, “stinky”, “farmy”). If your milk doesn’t look, smell or taste fresh, you should throw it out.
Will drinking spoiled milk make me sick?
Consuming spoiled milk in small amounts is not likely to hurt you. If you drink enough spoiled milk, you run the risk of developing food poisoning. If you believe you have food poisoning, we recommend you seek medical attention right away.
Does ultra-pasteurized milk spoil?
Yes. Ultra-pasteurization can give milk a longer shelf-life (prior to opening), but it can spoil just like pasteurized milk.
Does organic milk spoil faster than conventional?
No. Conventional and organic milk both contain naturally-occurring bacteria that will cause milk to spoil.
Does lower fat milk spoil faster than higher fat milk?
No. Several studies have been done asking this question, and results are inconclusive.