Appears in
On Food and Cooking

By Harold McGee

Published 2004

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Natto has been made in Japan for at least 1,000 years, and is notable for being distinctly alkaline (from the breakdown of amino acids into ammonia) and for developing a sticky, slippery slime that can be drawn with the tip of a chopstick into threads up to 3 ft/1 m long! As with tempeh, no salt is used and the product is perishable. The whole beans are cooked, inoculated with a culture of the bacterium Bacillus subtilis natto, and held at about 100°F/40°C for 20 hours. Some bacterial enzymes break down proteins into amino acids and oligosaccharides into simple sugars, while others produce a range of aroma compounds (buttery diacetyl, various volatile acids, nutty pyrazines), as well as long chains of glutamic acid and long branched chains of sucrose, which form the slimy strings. Natto is served atop rice or noodles, in salads and soups, or cooked with vegetables.