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⚠️ Are you taking anticoagulant medication (e.g. acenocoumarol, warfarin)? Natto is the richest natural source of vitamin K, which may reduce the effect of these drugs. Consult your doctor about your diet. See the important legal and medical information.
Drying natto without loss of quality is a technical challenge. The compounds present in fermented soy are sensitive to temperature. After years of trials we developed our own method of low-temperature convection drying. On this page we describe how it works.
The challenge: how to dry natto without losing its value
Traditional drying methods rely on high temperatures. For many products this is no problem, but the compounds present in fermented natto (vitamin K, enzymes, live bacterial cultures) are heat-sensitive. Too high a temperature leads to the degradation of these compounds and the loss of the features that set natto apart from other soy products.
Our process in brief
Method: convection drying at low temperature, in three stages
Raw material: fresh natto from fermented organic soy
Purpose: limiting the loss of compounds naturally present in fermented soy
What stays in the product: vitamin K in the K2 MK-7 form, nattokinase and live bacterial cultures
Development: research carried out between 2017 and 2018 together with the Lubuskie Centre for Agrotechnical Innovation and Implementation in Sulechów
Our solution: a three-stage process
Our drying process is slower than traditional convection drying, but thanks to this we control the temperature and humidity at every stage. With this method we obtain dried organic (BIO) natto, which serves as the base both for a food product and for supplements: capsules and natto tablets.
Three drying stages
- Preliminary stage: gentle handling of the raw material, gradual lowering of humidity at low temperature.
- Main stage: slow, controlled drying with precise measurement of parameters.
- Final drying: stabilisation and reaching the target crispness.
What we preserve in the product
- Nattokinase (a proteolytic enzyme formed during fermentation)
- Vitamin K (in the K2 MK-7 form)
- Live cultures of Bacillus subtilis Natto bacteria
- Natural taste without a “burnt” effect
Nattokinase does not hold an authorised EFSA health claim. This information is provided to describe the natural composition of the product.
Quality instead of shortcuts
Our process takes longer and costs more than standard drying. We chose it because it gives a product with a repeatable composition: we control temperature and humidity at every stage and we use no preservatives.
All our dried natto products are based on the same production process. The fact that we dry “our own way” has practical consequences: the same quality standard applies whether you buy natto loose, in capsules or in tablets.
About the author
Marek Kołodziejski, M.Sc. Eng., founder and creator of the Natto.pl manufactory, an engineer leading research and development work on the fermentation and drying of natto.
Author of the low-temperature convection drying technology described here, which protects vitamin K2 MK-7, nattokinase and live bacterial cultures.
For his research work and the production of fresh and dried natto as a functional food, he received the Economic Award of the Marshal of the Lubuskie Region (2024, Innovative Micro-enterprise category).
