Disclosed is a fat-free or low-fat yoghurt having a rich and creamy texture like yoghurts produced using whole-fat milk. A proper content of a milk protein, such as a defatted milk powder that has been deamidated with a protein deamidase, is added to a fat-free or low-fat raw material milk. Alternatively, a proper content of a milk protein, such as a defatted milk powder, is added to a fat-free or low-fat raw material milk, and the resulting mixture is subjected to a deamidation treatment with a protein deamidase so that the percentage of deamidation reaches a proper level. In this manner, a fat-free or low-fat milk raw material having a milk protein mass and a deamidation ratio both falling within proper ranges can be prepared. A yoghurt is produced using the milk raw material.
