Japan has 4 post-fermented teas.  3 of them are located in Shikoku Island where SONO is, and all those 3 are anaerobically fermented by lactic acid bacteria.  Those local lactic acid bacteria create unique sour tastes and multiple health benefits.

1. Manufacturing Steps of Japanese Post-fermented Teas

Each tea has unique making steps and all are handled by manual works.

Manufacturing Steps of Japanese Post-fermented Teas

(Horie et al. “Comparison of oxidant activities among four kinds of Japanese traditional fermented tea”,

Food Science & Nutrition, Vol.43, No.11, 2017; 5, P639-645, link to this research paper)

2. Major Tea Components in Japanese Post-fermented Teas

The fermentation processes reduce major tea components.

Catechins
Caffeine

(Horie et al. “Comparison of oxidant activities among four kinds of Japanese traditional fermented tea”,

Food Science & Nutrition, Vol.43, No.11, 2017; 5, P639-645, Link to this research paper)

3. Health Benefits of Ishizuchi Kurocha

Instead, lactic acid bacteria gives you multiple health benefits.

In addition to regulating the functions of the intestines, fermentation gives anti-allergy, obesity prevention, boosting immunity, and relaxing effects.

The following graphs show the effectiveness of anti-allergy and obesity prevention.

Degranulation of Mast Cell
Fat Accumulation

(Horie et al. “Evaluation of lactic acid bacteria and component change during fermentation of Ishizuchi-kurocha”,

Journal of Food Processing and Preservation, Vol.43, No.11, 2019, P7-8, Link to this research paper)