Sweet Rice Wine Ferment (Jiu Niang)

Ingredients

• 800 g Glutinous rice (round grain preferred)
• 8 g Sweet rice koji (Angie brand)
• 720 g Water
• 600 g Water

Method

fermentation of glutinous rice with koji spores produces a sweet, liqueur-like brine through enzymatic breakdown of starches into sugars and amino acids. Temperature control is non-negotiable — the koji works fastest between 28–32°C, where yeast fermentation runs in parallel. Too cold and the process stalls; too hot and you kill the microbes.

Cook the 800 g glutinous rice with 720 g water in a rice cooker using the standard setting. Spread it on a clean surface and cool to 30°C — warm enough to touch without discomfort, cool enough not to denature the koji spores. Dissolve the 8 g koji powder in 20 ml warm water and scatter it evenly across the rice, stirring thoroughly to distribute the spores. Add the 600 g water in a gentle mix — this liquid becomes the fermentation medium and the final broth. Let the rice sit for 2–3 minutes so it absorbs moisture evenly; uneven hydration creates dry pockets where mould can establish instead of the beneficial fermentation you want.

Pierce the rice with a wooden spoon handle to create a small well at the centre. This drainage hole lets you monitor fermentation visually and prevents anaerobic pockets. Transfer the mixture to a clean glass or ceramic vessel — plastic absorbs fermentation volatiles and taints the flavour — and cover with a lid or cloth. Maintain 28–32°C for 24–48 hours. Do not move the container; agitation breaks the delicate colony structure. Successful yeast-fermentation shows clear liquid pooling in the central depression, a subtle alcohol aroma (not vinegar or nail polish), and rice grains that hold their shape but soften slightly. If you detect sour or rotten smells, discard the batch.

After fermentation, refrigerate immediately to slow activity to a crawl. A secondary fermentation is optional — add 500 ml water for a thinner, higher-yield broth; ferment another 12–24 hours at room temperature if you want deeper flavour. To arrest fermentation permanently, steam the mixture for 10 minutes — the heat denatures the enzymes and kills remaining microbes — then cool and refrigerate. Store in the fridge for up to 10 days. Use only clean utensils to remove portions; cross-contamination reintroduces unwanted bacteria.