← Texture Programme · R&D Workbench · Homemade Ferments · Amazake

Amazake 甘酒

Sweet rice ferment — 0% alcohol. The F2 sugar-binder and Maillard-precursor in V1/V2 sears. Hold-at-temperature recipe — temperature precision matters more than time.

6-10 hoursat 55-60°C (rice cooker keep-warm)
15 minactive labor
0% alcoholenzymatic, NOT yeast-fermented
~RM 18cost per 600g yield
~RM 70 retail(75% cheaper)

§ 01 · WHAT IT ISAmazake — the saccharification ferment

Amazake is cooked rice held at 55-60°C with rice koji for 6-10 hours. The koji enzymes (amylases) convert rice starch into simple sugars (glucose + maltose), producing a thick, naturally-sweet rice porridge. Zero alcohol — this is enzymatic saccharification, not yeast fermentation.

Chemistry function
F2 sugar-binder · F4 ferment · Maillard precursor for N4 sear browning
Used in
V1 BALANCED (32g) · V2 TEMPEH-MAX (32g) · V5 omits amazake (the koji does the sugar work directly)
Halal status
✅ Yes — saccharification only, no alcohol byproduct. NOT to be confused with "sake amazake" which may have added alcohol.
Yield
~600g per batch (good for ~18 V1/V2 batches at 32g per batch)

§ 02 · ⚠ CRITICALTemperature is everything

Amazake's entire chemistry hinges on holding rice + koji at 55-60°C for 6-10 hours. Outside this range, you get a different (often inedible) outcome. You must verify your rice cooker's "keep warm" temperature BEFORE attempting this recipe.

Sweet spot
55-60°C — koji amylases at peak activity, produces glucose + maltose
Below 50°C
Bacterial growth risk (Lactobacillus + others). Sour off-flavors. FAIL.
Above 65°C
Koji enzymes denature. Saccharification halts. You'll get sweet-ish but flat-tasting rice porridge. FAIL.
Above 70°C
All enzymes dead. Just hot rice. HARD FAIL.
Verify your rice cooker BEFORE attempting Fill rice cooker with 500ml water, set to "keep warm", insert a probe thermometer, leave for 1 hour. Read the temp at hour 1.
  • 52-65°C — perfect, use this rice cooker
  • 45-52°C — too cool, do NOT use for amazake (use sous-vide instead)
  • >68°C — too hot, koji will denature
Most modern rice cookers (Tiger, Zojirushi, Cuckoo) keep-warm at 60-65°C — perfect range. Cheap models can vary.
Backup method: sous-vide If your rice cooker keep-warm is unreliable, use a sous-vide circulator set to exactly 58°C. Place rice+koji+water in a vacuum bag or zip-top bag, submerge for 6-8 hours. Sous-vide on Shopee MY — RM 250-400 for entry models.

§ 03 · INGREDIENTS3 ingredients · halal · plant-based

Cooked white rice (short-grain preferred)
200g cooked (about 100g raw rice cooked normally)
Use Japanese short-grain rice for best results. Long-grain (Basmati, jasmine) works but yields less starch conversion. Cool to ~60°C before mixing.
· Shopee MY · short-grain Japanese rice · RM 25-45 / kg
Rice koji (米麹 kome-koji)
200g · same koji as shio-koji recipe
Use 1:1 ratio koji to cooked rice — this is the key to enzymatic conversion.
· Marukura Foods Japanese Rice Koji 500g
· Isesou Miyako Rice Koji 200g/500g/1kg
Filtered water
200ml · at 60°C (NOT boiling)
Pre-heat in kettle, let cool ~30 seconds. Pouring boiling water onto koji kills enzymes instantly.

§ 04 · EQUIPMENTRice cooker + thermometer = the whole rig

Rice cooker with "keep warm" mode
Most modern brands keep-warm at 60-65°C (perfect). VERIFY YOURS FIRST with a thermometer (see §02).
· Shopee MY · Tiger rice cooker — gold standard
· Shopee MY · rice cookers with thermostat
· RM 150-280 entry · RM 400-900 premium
Digital probe thermometer
CRITICAL — must monitor temperature throughout fermentation
· Shopee MY · digital probe thermometer · RM 25-45
Wooden/silicone spatula
For stirring · NOT metal — same reason as shio-koji
Glass bottles or jars (for storage)
500ml-1L · sterilized · for refrigerated storage post-ferment

§ 05 · HOURLY PROCEDUREThe 6-10 hour saccharification

Hour 0 Mix + start hold 15 min · 55-60°C

Cook 100g raw rice with normal water ratio. Open the lid and let cool to ~60°C (verify with thermometer — should be hot but not steaming heavily).

While rice cools, pre-heat 200ml water to 60°C in a separate pot/kettle.

Add 200g rice koji to the cooked rice. Pour in 200ml warm water (60°C). Stir well with wooden spatula until uniform.

Verify mixture temperature is 55-60°C with probe thermometer. If too hot, wait. If cool, NOT a problem — keep-warm will bring it up.

Set rice cooker to KEEP WARM (not COOK). Leave lid slightly ajar OR wrap a wet cloth over the top to allow moisture exchange.

Initial mix: rice + koji evenly distributed, no dry pockets, smelling sweet-rice. Temperature reading: 55-60°C.
If your initial temp drops below 50°C, briefly press "COOK" for 1-2 minutes to bring temp up, then return to keep-warm. Watch the thermometer.
Hour 1-2 First stir + temp check 2 min

Stir gently with wooden spatula. Reading the thermometer at this point is critical.

Mixture should still be 55-60°C. Aroma shifts from raw-rice to sweet-rice.

Temp 55-60°C confirmed. Aroma sweetening.
If >65°C, lift lid for 2-3 minutes to vent heat. If <52°C, briefly cycle COOK for 30 sec.
Hour 3-4 Second stir + texture check 2 min

Stir. Notice: rice grains have started breaking down. Mixture is creamier. Sweetness is emerging — taste a small spoonful (it's safe to eat at this stage).

Should taste lightly sweet, somewhat watery still. NOT fully developed.

Distinctly sweet on the palate. Rice grains softening. No sour or alcoholic notes.
Hour 5-6 Third stir — minimum viable yield 2 min

Stir. Mixture noticeably thicker, sweeter, distinct amazake aroma (like sweet rice pudding).

This is the EARLIEST acceptable stop point. If you need amazake urgently, you can pull at hour 6 — but flavor is still developing.

Sweet, creamy, distinctly amazake. Rice grains 60-70% broken down.
Hour 7-8 Stir + taste — peak window 2 min

Stir. This is the typical peak — sweetness fully developed, koji enzymes have done most of their work, no off-flavors.

If running overnight from a 10pm start: hour 7-8 = 5-6am next morning. Pull, bottle, refrigerate.

Full sweetness, creamy thick texture, signature amazake aroma. Rice grains 80%+ broken down.
Hour 9-10 Maximum (optional — diminishing returns) 2 min

Some recipes go to 10 hours for "intense sweetness". Beyond that, you risk: koji enzymes start consuming the sugars they made, slight acidity emerging, flavor going "past peak".

For our hericium master formula, hour 7-8 is ideal. Hour 9-10 only if your koji is weaker than expected.

DONE Cool + bottle + refrigerate 10 min

Turn off rice cooker. Let amazake cool naturally to ~30°C (about 30-45 min on counter). Stirring once helps even cooling.

Transfer to sterilized glass bottles or jars. Seal airtight. Refrigerate immediately at 4°C.

Label with date + "amazake batch [N]". Use within 2-3 weeks refrigerated, or freeze in portions for 3-6 months.

Thick sweet rice paste, smooth, golden-cream color, smells like sweet rice pudding.

§ 06 · TROUBLESHOOTINGWhat goes wrong + how to fix

Tastes sour by hour 6 Temperature dropped below 50°C at some point — Lactobacillus took over. Discard. Next batch: check rice cooker temperature, may need to wrap in towel for insulation, or use sous-vide.
Tastes alcoholic / wine-like Same root cause — temp dropped, yeast/wild fermentation took over. Discard. Halal contamination risk — definitely do not use.
Not sweet enough after 8 hours Koji enzymes were too cold OR koji is weak/old. Try: extending to 10 hours · using fresh koji · verifying rice cooker really stays at 55-60°C (not 45-50°C).
Too thick / glue-like Too little water relative to koji+rice. Stir in 50-100ml warm water (60°C). Continue ferment.
Too thin / soupy Either too much water added at start, OR rice was undercooked (need fully softened rice). Cook 30 more minutes — koji will keep working and thicken via continued starch breakdown.

§ 07 · STORAGERefrigerated + freezer guidelines

Refrigerator (4°C)
2-3 weeks in airtight glass jar. Enzymes slow down but don't fully stop — flavor gradually sweetens further then plateaus. After 3 weeks, watch for slight alcoholic notes (wild yeast intrusion).
Freezer (-18°C)
3-6 months. Freezing halts all enzyme activity. Portion into ice cube trays (32g cubes = perfect single-batch dose for V1) for easy use.
When to discard
Sour smell · alcoholic smell · visible mold growth · separation that looks like pink/red layer (rare but indicates contamination).
Travel / transport
Keep cold (cooler bag) under 10°C. At room temp, enzymes resume and can over-ferment.
Pro tip · pre-portioned ice cubes Freeze in 32g cubes (a standard ice cube tray works). On trial day, pull 1 cube → V1 batch ready. No measuring, no waste.

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