PURPOSE: A plant to be extracted is dipped in a saccharide solution for extraction and a microorganism producing gluconic or citric acid is made to act on to effect high-efficiency extraction of plant active ingredients, thus giving a tasteful saccharide solution.

CONSTITUTION: A plant to be extracted such as fungi or herbs are cut into samll pieces, when needed, and dressed with sucrose for preparation. Then, a microorganism producing gluconic acid is inoculated and they are laid in a storage house as a seed for citric acid fermentation. The inoculation of bread mold to plants treated with sucrose is effective as a seed for citric fermentation. Thus, ingredients in plants are extracted in the course of fermentation and aging to remove bad smell, taste, bitterness of the plants to give a saccharide solution with refresh tastes.