How does natto taste

Content on WhatAnswers is provided "as is" for informational purposes. While we strive for accuracy, we make no guarantees. Content is AI-assisted and should not be used as professional advice.

Last updated: April 8, 2026

Quick Answer: Natto has a distinctive taste characterized by strong umami, pungent ammonia-like aroma, and slimy texture. The flavor develops through fermentation where Bacillus subtilis var. natto bacteria break down soy proteins into amino acids like glutamate, creating savory notes. Traditional Japanese natto typically contains 1-2% salt and ferments at 40°C for 16-24 hours, producing its signature sticky strings. Many describe it as an acquired taste with earthy, nutty undertones alongside its fermented sharpness.

Key Facts

Natto fermentation uses Bacillus subtilis var. natto bacteria at 40°C for 16-24 hours
Traditional natto contains 1-2% salt concentration
Fermentation breaks down 30-40% of soy proteins into amino acids
Natto production dates back to Japan's Edo period (1603-1868)
Contains 100-200 billion viable bacteria per 50g serving

Overview

Natto is a traditional Japanese fermented soybean food with origins tracing back over 1,000 years. Historical records suggest natto production began during Japan's Heian period (794-1185), with the modern method developing during the Edo period (1603-1868). The food is made by steaming whole soybeans and inoculating them with Bacillus subtilis var. natto bacteria, which ferment the beans at approximately 40°C. This fermentation process creates natto's characteristic sticky strings (polyglutamic acid) and strong aroma. In Japan, natto consumption averages about 7.5 billion packs annually, with regional variations in preparation methods. The Kanto region typically produces smaller bean varieties while Tohoku regions use larger soybeans. Natto is traditionally served with rice for breakfast and is considered a staple food in Japanese cuisine.

How It Works

The fermentation process begins with selecting high-quality soybeans, typically Japanese varieties like Miyagino or Tamba. The beans are soaked in water for 12-24 hours, increasing their weight by 2-2.5 times, then steamed at 100°C for 6-8 hours until tender. After cooling to 40°C, the beans are inoculated with Bacillus subtilis var. natto spores at a concentration of approximately 10^5-10^6 spores per gram of soybeans. The inoculated beans ferment in controlled conditions at 40°C with 85-90% humidity for 16-24 hours. During fermentation, bacterial enzymes break down 30-40% of soy proteins into amino acids, particularly glutamate which creates umami flavor. The bacteria also produce polyglutamic acid, creating the characteristic sticky strings, and vitamin K2 (menaquinone-7). After fermentation, natto is cooled to 0-5°C to stop bacterial growth and develop flavor over 1-3 days of aging.

Why It Matters

Natto holds significant cultural importance in Japan as a traditional breakfast food consumed by approximately 60% of Japanese households regularly. Nutritionally, it provides complete protein, fiber, and is Japan's richest natural source of vitamin K2, containing 800-1000 μg per 100g serving. The vitamin K2 supports bone health and cardiovascular function. Scientific studies show regular natto consumption may reduce osteoporosis risk by 80% in postmenopausal women and lower cardiovascular disease mortality. The natto industry generates over ¥100 billion annually in Japan, with major producers like Mizkan and Takahashi maintaining traditional methods while expanding globally. Beyond Japan, natto has gained international attention for its probiotic benefits and unique umami flavor profile, influencing fermented food trends worldwide.