PURPOSE: To obtain the powder having various kinds of flavor-remedying effect, food preservative effect, or cooking promoting effect, useful for e.g. highly safe food additives by extracting with a solvent microbial post-fermented tea from green tea followed by lyophilizing the resultant extract liquor.

CONSTITUTION: Post-fermented tea obtained by stacking green tea to make microbial post-fermentation is boiled in hot water and extracted, and the resulting extract liquor is lyophilized to obtain the objective soluble powder. The powder has the following advantages: (1) takable as a beverage after being dissolved in water; (2) retaining the taste, flavor, shape and preservability of various kinds of food by addition thereto; (3) capable of shortening cooking time and enabling cooking adequately soft, frying, or steaming; (4) capable of making drinking water having metabolism promoting activity; (5) simultaneous having various kinds of flavor-remedying effect, food preservative effect and cooking promoting effect etc., and (6) useful as e.g. highly safe food additives.