A method for controlling the flavor balance of a liquid food or beverage, said method being characterized by comprising contacting a starting material of the liquid food or beverage with a hydrogen-containing gas. An agent for controlling the flavor balance of a liquid food or beverage, said agent being characterized by comprising a hydrogen-containing gas as an active ingredient. Controlling the flavor balance is preferably one or more performances selected from the group consisting of improving sweetness, improving body taste, improving saltiness, improving crispness, improving aroma, improving mildness in carbonic acid stimulation, reducing bitterness, reducing astringency, reducing miscellaneous taste, reducing sourness, reducing meat smell, reducing heated smell and reducing offensive smell derived from a plant. By the method and agent according to the present invention for controlling the flavor balance of a liquid food or beverage, preferable flavor of a liquid food or beverage can be improved and, at
