pose a health risk. The stock is then refrigerated or frozen until required. Refrigerated stocks may be kept for up to three days, while frozen stocks may be kept for up to a month. If the stock is to be kept longer it must be boiled before being returned to storage. In theory, a master stock could be sustained indefinitely if due care is taken to ensure it does not spoil. Otafuku, an oden restaurant in Japan, has kept its broth simmering since 1945 (an earlier batch was destroyed in WWII). There are claims of master stocks in China that are hundreds of years old, passed down through generations of cooks in this way. See also Perpetual stew References External links Neil Perry's Master Stock recipe Cheong Liew's recipes for Master Stock and Master Stock dishes Stock (food)