The sticky threads that stretch from the natto beans when they are lifted are proof that the natto bacillus has propagated successfully in the soybeans and produced fermentation. Many people who love nattto feel that the natto becomes more delicious the more times it is stretched.

The key to producing strong threads is to ensure a temperature and humidity that are ideal for propagation of the natto bacillus, enabling it to function effectively. Thorough temperature control and quality control will ensure ideal natto fermentation.