PROBLEM TO BE SOLVED: To enhance a shelf life of food fermented by rice malt without heating the food as practiced in jam production and without adding salt in a production process of the food, while solving a problem that a lot of time and labor is required for temperature control and refrigeration equipment in a fermentation step in a conventional production method of food fermented by rice malt.SOLUTION: A ratio and a timing of adding sugar are adjusted in a production process of food fermented by rice malt, and an osmotic pressure is raised by hydrolysis of the rice malt to enhance a shelf life. Grained vegetable, or fruit or its skin is mixed with sugar and then it is mixed with the rice malt or white rice malt to ferment under the condition of a hydrogen-ion exponent (pH) of 4.5 or less. Thus, the osmotic pressure is raised by hydrolysis of the rice malt to enhance a shelf life. Use of the white rice malt which contains much citric acid, instead of the rice malt, further raises the effect.
