The invention relates to a liquid treatment system, in particular for concentrating milk, and method therefor. The system according to the invention comprises: - an inlet configured to receive fresh raw milk - a pressure vessel connected to the inlet, wherein the pressure vessel is provided with a pressure system configured to realize a pressure of at least 10 bar in the pressure vessel - a reverse osmosis membrane for filtering the raw milk - a pump for pumping the raw milk under pressure out of the pressure vessel and through or along the reverse osmosis membrane and - a permeate outlet for the separated water and a milk outlet for the concentrated milk.
