PROBLEM TO BE SOLVED: To provide techniques for improving the taste of beverages containing bitter substances as well as citric acid and/or malic acid by relieving drawbacks thereof such as prominent unpleasant strong sourness and a monotonous flavor of the whole beverage that is caused by reduced bitterness.SOLUTION: The taste of beverages containing bitter substances as well as citric acid and/or malic acid can be improved by adding a small amount of a thickener thereto.