Koji: Production and Applications opens the second part of the Terra Vegan series and takes the reader into the oldest transformation in cooking, the one that happens before the stove is lit. Its protagonist is Aspergillus oryzae, the mould that has quietly worked rice in Japan for centuries and that today becomes the most powerful tool in plant-based cooking.
Nemo starts from history and biology: how the fungus lives, what its enzymes actually do, why amylases turn starch into sweetness, proteases build umami and lipases release the aromas hidden in fats. This is not theory for its own sake: understanding what happens inside the grain is what allows you to govern the process instead of submitting to it.
The heart of the book is the production of kome-koji step by step, ten phases described one by one: choosing and washing the rice, soaking, steaming, cooling, inoculation, the first twenty-four hours, the turning, the final maturation and how to recognise a successful batch. Each phase has its own timings, temperatures and signals to watch.
Drying and stabilisation follow, that is how to turn a living and perishable product into an ingredient that keeps for months, together with the preparation of starter powder: milling, sieving, dosage and storage.
Five base recipes put koji to work straight away: fresh kome-koji, shio koji, amazake, koji water and koji paste. They are the foundation on which every later volume in the series rests.
The book closes with a chapter on safety treated as knowledge rather than fear: why Aspergillus oryzae is safe, what the real risks are, when a batch can be saved and when it must be discarded, and how to spot a process problem before it becomes damage.
