Yamaroku Soy Sauce Tsuru-bishio | ヤマロク醤油 鶴醤

Their signature soy sauce Tsuru-bishio '鶴醤'
The method starts with fresh soy sauce aged 1-2 years, which is returned to the barrel, fortified with additional soybeans and wheat, and aged for another 2-3 years. Using additional ingredients, time, and nature’s power, the salt from the original aging process develops into incredible depth, aroma, and smoothness.

Details
Weight: 500ml

Ingredients
Soya, Wheat, Salt
Contains: Soy

Artisan 
Yamaroku
Establishment: About 150 years ago (no public record left)
Hidden facts:
They produce all of their soy sauce in 3000-6000 litters of wooden barrel.
All fermented condiments are made by the power of microorganisms like lactobacillus and yeast fungus.
Maintain the ideal environment, they will produce the most delicious condiments. That's why it's crucial to use wooden barrel and not plastic.
However, it is extremely difficult to control the temperature in these barrels, requiring time and maintenance, but we still insist on using them today.