PURPOSE: To prepare a vinegar rich in a nutritive value of mineral safely at a very low cost, by incorporating a food containing much mineral and a seaweed into a vinegar.

CONSTITUTION: The eggshell of a hen's egg or other poultry egg or a bone or shell of a fish or shellfish containing much mineral is added to the fermentation liquid of a vinegar and dissolved in an organic acid, e.g. acetic, lactic or malic acid, in the vinegar. A seaweed, e.g. a sea tangle, wakame or hijiki (Hizikia fusiforme), is added to the solution to extract the mineral from the seaweed by the vinegar fermentation. Thus, a vinegar rich in nutritive value containing much mineral can be obtained.