Which form of koji → what you can make
| Form | What you can make | Time needed |
|---|---|---|
| Rice koji (fresh or dried) | Amazake, shio koji (homemade), salt rice koji, miso, sake, koji bread | 8 h (amazake) to 7–10 days (shio koji) |
| Shio koji (paste) | Marinades, glazes, quick pickles, dressings, sauces, koji butter | 30 min–overnight |
| Amazake (sweet fermented rice drink) | Dressings, baking (sweetener replacement), smoothies, hot drink, bread dough | Ready to use |
For a side-by-side comparison of the two most common forms, see Koji vs Shio Koji.
1. Marinades
Shio koji marinade works on the same principle as dry-brining but adds enzymatic tenderization. Aspergillus oryzae proteases in the koji break down surface proteins into free amino acids over 6–16 hours, producing deeper browning and rounder umami when the protein hits heat.
Shio Koji–Marinated Chicken
Ratio: 10% shio koji by weight of protein. For 300g chicken thighs: 30g shio koji (approximately 2 tablespoons).
Pat the chicken dry. Coat all surfaces evenly with shio koji. Place in a zip bag or covered container. Refrigerate for 6 hours minimum, overnight preferred (8–12 h). Wipe off excess shio koji before cooking — any residue burns quickly at high heat due to the free amino acids and sugars.
Cook in a dry skillet over medium-high heat (180–190°C) for 4–5 minutes per side. The crust develops faster and darker than on plain salt chicken. Internal temperature target: 74°C.
Result: Noticeably more tender than salt-brined chicken, with a sweet, caramelized exterior. The interior stays juicier because enzymatic action partially relaxes muscle fibers before cooking.
→ Full recipe and timing variations: Koji Marinated Chicken. For shio koji marinated salmon using the same 10% ratio but with a shorter 4–6 h window, see Koji Marinated Salmon.
Shio Koji Chicken Thighs (Oven)
Ratio: 10% shio koji by weight. 400g thighs = 40g (2½ tablespoons).
Marinate 8–12 hours refrigerated. Roast skin-side up at 200°C (convection) for 25–30 minutes without turning. The skin crisps without added fat because the enzyme-loosened surface proteins brown efficiently. Rest 5 minutes before serving.
→ Step-by-step method with bone-in vs. boneless timing: Shio Koji Chicken.
2. Glazes
Shio koji glazes work as finishing applications applied in the last 2–3 minutes of cooking. The free sugars in koji caramelize quickly, so apply only at the end to avoid burning.
Miso–Koji Glaze for Fish
Ratio: 2 tbsp shio koji + 1 tbsp mirin + 1 tsp sake. Stir to combine. Makes enough for 2 fillets (approx. 250g total).
Pat fish fillets (salmon, cod, black cod, sea bream) completely dry. Line a baking tray with foil and place fillets skin-side down. Brush the glaze across the top surface in a thin, even layer. Broil at high heat (230°C top element) for 5–7 minutes — watch carefully after 4 minutes. The glaze should turn deep amber and smell of caramel and fermentation, not smoke.
Result: The shio koji provides salt, umami, and enzymatic surface prep; mirin adds sweetness and gloss; sake thins the paste and adds aroma. The combination is considerably more complex than a plain miso glaze because koji's lower fermentation temperature preserves more volatile aromatics.
→ For how shio koji behaves as a marinade vs. glaze: How to Use Shio Koji.
3. Rice Koji Dishes
Rice koji (kome koji) is the raw material. These recipes use it as an active ingredient rather than a finished condiment. The key variable is temperature: koji amylases are most active at 55–60°C.
Amazake (Sweet Fermented Rice Drink)
Ratio: 200g short-grain rice (cooked to 300g wet weight) + 100g rice koji + 400ml warm water (55°C).
Cook the rice. Cool to 60°C. Add the rice koji and warm water. Stir thoroughly. Hold at 55–60°C for 8 hours — use a rice cooker on “keep warm,” an Instant Pot yogurt setting, or a covered pot wrapped in towels and placed in a 60°C oven. Stir every 2 hours. After 8 hours the mixture should be thick, very sweet, and porridge-like. No sugar is added; all sweetness comes from amylase converting starch to glucose.
Consume as a warm drink, thin with water to taste, or refrigerate for up to 5 days. For a richer version, blend smooth before serving.
→ How to use amazake beyond a drink: How to Use Amazake.
Salt Rice Koji (Fermented Rice Seasoning)
Ratio: 200g rice koji + 60g fine sea salt + 250ml water. This is the base recipe for making shio koji at home.
Combine in a clean glass jar. Stir until the salt dissolves and the koji is fully submerged. Cover loosely (not airtight — CO2 needs to escape). Leave at room temperature (20–25°C). Stir once daily. After 7–10 days the mixture becomes porridge-like and smells sweet, fruity, and slightly lactic. Refrigerate to stop fermentation. Keeps 3–6 months refrigerated.
→ Complete fermentation timeline and troubleshooting: How to Make Shio Koji. To make fresh rice koji from scratch: How to Make Koji.
4. Pickling with Shio Koji
Shio koji pickles (shio koji-zuke) are among the fastest Japanese pickles. The salt in shio koji draws out moisture by osmosis; the koji enzymes simultaneously break down pectin in vegetable cell walls, softening texture and releasing flavor compounds.
Quick-Pickled Cucumber
Ratio: 1 tablespoon shio koji per 200g vegetables. For one medium cucumber (180–200g): 1 tbsp shio koji.
Slice cucumber into 3mm rounds or cut into spears. Toss with shio koji in a bowl or zip bag, coating evenly. Leave at room temperature for 30 minutes for a lightly salted, crunchy result. For a softer, more fully pickled texture: refrigerate for 2–4 hours. Rinse briefly before serving if the surface tastes too salty, or serve as-is for full intensity.
Other vegetables: Daikon (1 tbsp shio koji per 200g, 2 h), carrot (1 tbsp per 150g, cut into matchsticks, 1 h), cabbage (2 tbsp per 300g, massage lightly, 30 min).
→ For the full pickling technique including long-fermented vegetables: How to Use Koji.
5. Dressings and Sauces
Shio koji replaces salt, adds umami, and provides a subtle fermented depth in dressings that plain salt cannot replicate. It emulsifies moderately well due to the protein fragments in the paste.
Shio Koji Dressing
Ratio: 1 tbsp shio koji + 2 tbsp rice vinegar + 1 tbsp sesame oil. Whisk together. Makes enough for 2–3 salad servings.
This base dressing works on green salads, shredded cabbage, cold soba, or blanched spinach. The shio koji provides salt and umami; rice vinegar provides clean acidity; sesame oil provides richness and aroma.
Variations: Add 1 tsp grated ginger for a sharper dressing on raw vegetables. Add ½ tsp toasted sesame seeds and 1 tsp mirin for a rounder, sweeter version for grain bowls.
Keeps refrigerated for up to 2 weeks in a sealed jar. The umami from the koji deepens over the first 2–3 days as residual enzymes continue working at refrigerator temperature.
→ How shio koji interacts with acids and fats: What Is Shio Koji.
6. Baking and Other Uses
In baking, koji enzymes convert starch to sugar and break down gluten slightly, producing a more tender crumb and accelerating browning. The salt in shio koji also functions as a dough conditioner.
Koji Bread
Ratio: Add 30g dried rice koji per 500g bread flour. Reduce added salt by 3g (koji contributes roughly 3g salt per 30g koji if using shio koji; adjust if using unsalted rice koji). Mix koji in with the flour before adding water.
Standard bread method applies. The fermentation window is unchanged — koji enzymes act slowly at room temperature and do not disrupt gluten development significantly. The result is a slightly sweeter, more complex crumb with a faster golden crust due to enzyme-produced sugars reacting in the Maillard reaction at oven temperature.
Koji Butter
Ratio: 1 tablespoon shio koji per 100g unsalted butter (room temperature).
Beat softened butter with shio koji until fully combined and fluffy, about 2 minutes by hand. The koji enzymes continue very slowly in the fat matrix; after 24 hours refrigerated, the butter tastes noticeably more umami-rich and complex. Shape into a log in plastic wrap and refrigerate for up to 2 weeks, or freeze for 3 months.
Use on grilled corn (melt over hot cobs directly), pan-sauced fish (finish 1 tsp into the pan off heat), or steakhouse-style compound butter on seared beef.
→ More uses for koji in Japanese pantry cooking: How to Use Koji.
Shop shio koji paste and rice koji on Amazon →
Frequently asked questions
What is the ratio for shio koji marinade?
Use shio koji at 10% of the protein weight. For a 300g chicken breast, that is 30g (about 2 tablespoons) of shio koji. Coat evenly, refrigerate for 6 hours minimum or up to overnight (12 hours). Beyond 16 hours the enzymes begin to over-tenderize the surface, producing a slightly mushy texture on fish. Chicken and pork tolerate up to 24 hours.
Can I use dried rice koji instead of fresh rice koji in recipes?
Yes. Dried rice koji (kome koji) rehydrates in 30 minutes in lukewarm water. Use the same weight as fresh after rehydrating. Enzymatic activity is slightly lower in dried koji — expect 80–90% of the tenderizing effect compared to fresh. For amazake, rehydration before use is mandatory; add the dried koji directly to hot rice and it will rehydrate during the 8-hour fermentation process.
How long does shio koji dressing keep?
Shio koji dressing (shio koji + rice vinegar + sesame oil) keeps for up to 2 weeks refrigerated in a sealed jar. The salt in shio koji acts as a preservative. Shake or whisk before each use as the sesame oil separates. Add fresh ginger or garlic only if using within 3 days, as those cut aromatics spoil faster than the base dressing.
What is the difference between koji food and shio koji food?
Koji food (rice koji, kome koji) refers to dishes made with the raw, unsalted koji grain — amazake, salt rice koji, homemade shio koji, sake, and miso. Shio koji food is the narrower category of dishes using the ready-made fermented paste: marinades, glazes, quick pickles, and dressings. The key distinction is enzymatic state: raw koji has full active protease and amylase activity; shio koji enzymes continue working at low temperatures but are partly slowed by the salt concentration.
Why does koji-marinated chicken brown better than plain salt chicken?
Koji proteases break down surface proteins into free amino acids, particularly glutamate and lysine. Lysine and other free amino acids participate in the Maillard reaction more readily than intact proteins, accelerating browning at the same temperature. A koji-marinated chicken thigh develops a deeper, faster crust in a skillet at 180°C compared to a salt-only chicken thigh, with measurably more aroma compounds produced in the same cooking time.
Can I substitute shio koji for miso in a glaze recipe?
Yes, but adjust for salt and sweetness. Shio koji is saltier and less sweet than white miso by volume. In a miso glaze recipe calling for 2 tbsp white miso, use 1.5 tbsp shio koji and add 1 tsp mirin to compensate for the lost sweetness. The texture will be thinner — shio koji is more liquid than paste — so brush a slightly thicker layer or reduce the glaze briefly before applying.
What can I make with leftover amazake?
Amazake works as a natural sweetener in baked goods (replace 50g sugar with 100ml amazake in simple cakes or muffins), as a base for smoothies, thinned with milk as a hot drink, or stirred into salad dressings in place of honey or mirin. It also works in bread dough — substitute 50ml amazake for 50ml water and 1 tsp sugar in a standard loaf recipe for a slightly softer, more complex crumb.
Where to go next
- What Is Koji — the mold behind all koji food: how Aspergillus oryzae works and why it matters
- What Is Shio Koji — composition, enzyme chemistry, salt content, and storage
- How to Use Shio Koji — deeper coverage of marinades, curing ratios, and vegetable applications
- How to Use Koji — raw rice koji applications beyond shio koji
- Koji vs Shio Koji — when to use each form and what each one can and cannot do
- What Is Miso — the koji fermentation that takes months instead of days
- Guides Hub — all ingredient and technique guides