To provide a means for producing a vinegar having high extract content and emitting fragrance suitable as a vinegar having the taste and flavor of the raw materials in a high extract environment without restriction of amino acid content and nonfermentative sugar content and provide a means for producing the high-extract vinegar without causing the lowering of the fermentation efficiency.

A bacterial strain for high-acid fermentation is used in the fermentative production of a vinegar having an extract concentration of 3-13 w/v%. The extract concentration in the fermentation liquid is increased at a rate of ≤5.0 w/v% per hour in the fermentation stage.