Abstract: A process for the preparation of an essentially bacteria-free colostrum by means of microfiltration, which process includes that defatted, natural colostrum (first milk) is poured into a balance tank; subsequently the feeding pump is pumping the concentrate to a booster pump; the booster pump circulates the concentrate across a filter membrane wherein the pressure difference in the membrane rendered filtration of the concentrate possible; the concentrate is flowing across a heating/cooling unit to keep a constant process temperature before the concentrate returns to the booster pump; filtrated colostrum (the filtrate) circulates across the filter membrane to keep a constant transmembrane pressure; the filtrate is drained without pressure loss on the filtrate side of the filter.