A method is disclosed in which milk-substitute in liquid concentrate form is manufactured by: hydrolysing lactose within whey or a whey derivative to create simple sugars; adding protein; and reducing the pH of the resultant liquid to a pH at or below pH 4.5. The whey derivative can be whey permeate and the loss of protein which arises as a result of its use can be compensated for by the addition of soya or other vegetable protein. Further steps include the use of an enzyme for hydrolising the lactose, which then has an action of subsequently recombining the simple sugars into oligosaccharide polymers. Organic acid can be added to compensate for the resulting reduction in osmolarity.