Fermentation can be traced back through humanity for years and years, and while it’s used for a variety of different purposes, many cultures use it for one main thing – food preservation.
In fact, traditional fermentation processes came about by accident. When food availability was scarce or there were no storage methods (like refrigeration) fermented foods were a necessity to make foods last. What’s more, is that ancient cultures didn’t walk around with hand sanitisers and antibacterial substances all the time, so foods would more readily come into contact with environmental microbes which would naturally ferment the ingredients.
Fermentation requires living microorganisms in order to do its job – this means bacteria, fungi or yeasts. If you’ve heard the terms scoby, kefir grains, koji or ‘the mother’ thrown around, these are simply names for the different types of living microorganisms that ferment a variety of food.
Fermentation in Japanese culture and koji
Pronounced ko·ji | \ˈkōjē\
What’s really interesting is that despite geographical separation, almost every culture has its own traditional fermented food or drink. This may be Persian doogh, Indian dosa, Icelandic skyr, Korean kimchi or, of course, Japanese miso.
In Japan, the living microorganism process of fermentation is called koji. In fact, koji is used to make all sorts of foods commonly found in Japanese cuisine – think soy sauce, mirin, rice vinegar, amazake, sake and miso.
Evidence of koji has been traced back to 9,000 years ago in both ancient Chinese and Japanese cultures. Koji describes a mixture of partially or fully cooked rice, barley or soybeans that are injected with a fungus. The cooked grains act as a substrate, meaning they basically feed the microorganisms, allowing them to multiply and produce enzymes which act to break down starches and proteins. The result? An incredibly rich umami flavour profile which is unique to these foods. So, there we have the catalyst for future fermentation processes!
Then, this mixture of grain and mould AKA koji is added to another food product – in the case of miso this will be soybean paste and salt – where it undergoes more fermentation, transforming the initial ingredients’ texture and flavours until it’s ready to be eaten or used in cooking. Additionally, you are creating a powerhouse of enzymes and microbial flora that make fermented foods an excellent addition to your diet.
One of the best things about fermented foods is the history and culture that comes along with it. Often the microorganisms we use to ferment today are a direct lineage from the microorganisms that started naturally fermenting foods all those years ago. So, every time you use a spoonful of miso, you’re adding a delicious umami spoonful of history and love to your cooking.