The invention provides a protocol for pasteurizing mother's milk that maximizes the retention of protein bioactivity while removing effective amounts of dangerous bacteria. This includes an optimal temperature at which the milk is held during pasteurization, as well as a very rapid rise to and then fall off from that holding temperature. The invention also provides a method for adjusting the fat content of mother's milk. This includes a method to standardize the energy content of mother's milk by adjusting the fat content by separating the milk contents, as by centrifuging, into at least fat and skim milk layers. The volume of skim milk is adjusted to meet the desired fat concentration, i.e., skim is removed to increase, or added to decrease.