Last time, I talked about dried meat made in the countryside of Brazil. Drying meat isn’t very common in Japan. However, when  we think about dried fish, which is commonly eaten in Japan, it doesn’t seem too unfamiliar. Whether it’s fish or meat, there’s no doubt  that the key point lies in the salt content. In the West, the focus is on meat as salted products, whereas in Japan, it’s fish and vegetables,  but fundamentally, the process isn’t all that different. Even with pickled foods, if the salt content isn’t balanced correctly, it can end  up spoiling instead of preserving. This all comes down to the salt concentration. If done well, it results in fermentation, but if done poorly, it leads to decay.

So, are “fermentation” and “decay” really different? These two names are merely labels created from a human point of view. If it’s beneficial to humans, we call it fermentation; if it isn’t, we call it decay.  Fermentation refers to something that smells good, tastes delicious, and is safe without toxins. Salt concentration  plays a major role in this. I previously mentioned dried meat made in the countryside of Brazil, which is often swarmed by flies,  but despite that, it doesn’t spoil and can be eaten deliciously. While harmful bacteria certainly attach to the fly-covered meat, these  bacteria cannot proliferate due to the high salt content and sunlight exposure, ultimately rendering it safe as food. Therefore,  both fermentation and decay are quite arbitrary terms, invented by humans. The distinction is abstract and heavily influenced  by the local food culture of each region.

In Japan, familiar examples of this concept are natto and kusaya. To foreigners, these are clearly seen as spoiled. On the  other hand, consider Sweden’s surströmming (fermented herring in a can), known as the world’s smelliest food, and Korea’s hongeohoe  (fermented skate), which ranks second globally in terms of odor—there are countless examples like these. From a Japanese perspective,  it might seem obvious that such foods are spoiled, yet each has its own cultural significance in terms of cuisine. Ultimately, all of these  processes are driven by microorganisms that cause various changes. If the result is delicious, we call it fermentation; if it tastes bad,  we call it decay. It’s really a highly subjective distinction.

My father often used to say, “There’s nothing dirty about delicious food.” It makes me think of him, even though he passed away 30 years ago.  I remember once when I caught a 40-kilogram stingray at a nearby beach. I brought home only the edible parts and, not knowing  how to make hongeohoe (fermented skate), I processed it into fish cakes like kamaboko or hanpen. It took a lot of time. Catching it was a huge challenge, and I decided I never wanted to take the life of that kind of fish again. Proteins are made up of chains of amino acids. When enzymes from microorganisms break those chains, amino acids are released, and that’s  what gives the food its umami flavor.

Fermented foods are unique to each country, making them extremely interesting. However, Manuka honey, being a fully mature  raw honey with a sugar concentration of over 80%, is inhospitable to microorganisms. Interestingly, if diluted with water, it can ferment and turn into alcohol.