Koji Collaboration

Japan is the home of plenty of fantastic fermented foods. And all the ones you’ve heard of – soy sauce, miso, sake, mirin, vinegar, and amazake – and use every week are made using one amazing microorganism. 

Koji – or aspergillus oryzae – if you prefer is a type of mould that breaks down carbohydrates into sugar. And sugar – as we all know – is essential in the fermentation process. 

Similar to how beer makers use yeast, Japanese fermenters use koji to turn different grains – usually rice or soybeans – into the delicious sauces and pastes you buy of the shelves. But there’s more to delicious umami-packed sauces and pastes besides their taste, they have some great health benefits too.

Packed with antioxidants, amino acids and probiotics, fermented foodstuffs have a heap of beneficial elements that have been linked with several health benefits. They’re universally lauded for improving gut health and helping with good digestion.

Koji has become such a popular health product that it’s now being sold not just as a fermentation starter but as it’s own standalone products. Supermarkets now sell shio or shoyu koji, a viscous mix or koji and salt or soy sauce. They’re a great substitute for soy sauce or seasoning in recipes or you can go hardcore and take a shot each morning to give your gut a pick me up. 

If you’re into pickling, try mixing the veggie of your choice – carrots, cabbage, cucumber or daikon – leaving them to soak in some salt koji for a couple of hours. 

But where koji sauces shine is in dressings, marinades and other sauces. They’re umami and salt-laden base that adds depth of flavour to anything you’re making. 

I would recommend adding koji sauces when marinating any of your cheaper but oh so fashionable cuts of meat, like a hanger or skirt steak. The Koji tenderizes the meat and relaxes the fibres, making it easier to enjoy these incredibly flavourful but generally tougher cuts.