To provide a liquid impregnation method for beans for surely and rapidly impregnating the dried beans with liquid and retaining flavor for a long period of time through a relatively simple method, relating to a production method for imparting flavor to dried coffee beans through a vacuum impregnation method.

The liquid impregnation method for beans comprises sufficiently reducing pressure in a vacuum bag where beans such as dried coffee beans are stored together with liquid to be added and thereby even minute gaps between beans in the inner part of the beans are vacuumed. In such a condition, when air pressure is applied to the vacuum bag to be shrunk after tightly closing the vacuum bag, a small amount of solution which is charged in advance is absorbed into the minute gaps of each of the beans to be impregnated. The added liquid penetrates into the dried beans by such a vacuum impregnation method, and thereby the objective liquid instantly penetrates into the material such as the dried beans so as to surely and easily perform treatment in a short time period. Further the impregnated liquid components hardly disappear and the flavor and/or the taste are kept longer because the liquid are impregnated into the minute gaps under negative pressure-condition.