A concentrated milk-base composition which includes stabilizing salt, sugar and flavoring agent components is prepared for flavoring a beverage, particularly for flavoring a coffee or tea beverage. The composition is prepared by mixing and homogenizing a milk fat with skimmed milk to obtain a milk base, subjecting the milk base to evaporation to obtain a concentrated milk base, homogenizing the concentrated milk base, cooling the homogenized milk base, adding a stabilizing salt and sucrose in dry form, and in one embodiment, a flavorant agent is added also to the cooled milk base and then the composition is heated to sterilize it, the sterilized composition is homogenized and then is filled in a package, and in another embodiment, a flavorant composition is added aseptically to the sterilized composition before homogenizing.