A soluble, dairy additive designed specifically for use in vending machines that produce beverages includes or consists of agglomerated dry milk powder. The agglomerated dry milk powder consists of dairy ingredients only (e.g., dried milk) and has a scorched particle mass not greater than fifteen milligrams and a particle bulk density in the range of 0.25 g/cc to 0.34 g/cc. The powder may be combined with coffee and/or other ingredients, either prior to being placed in a vending machine or upon demand within a vending machine, to vend a consumable beverage from the vending machine. Accordingly, the agglomerated dry milk powder may be pre-mixed with one or more independent flavoring ingredients, such as coffee, sugar, or cocoa powder, to provide a mixture formulated specifically for use in the vending machine.