Mount Kenya Long Life UHT Milk is milk that has been processed at ultra high temperature (UHT). The sterilization is made through rapid heating of milk to a temperature of at least 135°C, keeping it there for a few seconds, and then quickly cooling it down to ambient temperature. UHT milk is a rich source of a number of essential nutrients including calcium, phosphorus, potassium, riboflavin, zinc, vitamins A and B12, magnesium, carbohydrates, and protein. Sterilization makes milk lighter as once you have treated milk at ambient temperature, the number of microorganisms turns almost zero.