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Shio-koji 塩麹

Salty koji ferment. The N1 free-Glu liberator in our V1/V5/V2 master formula. 7-10 day room-temperature enzymatic ferment — no microbes, no alcohol, halal-compatible.

7-10 daysroom temp 20-25°C
15 minactive labor day 1
2 min/daydays 2-7 stir
~RM 30cost per 450g yield
~RM 50 retail(40% cheaper)

§ 01 · WHAT IT ISShio-koji — the Japanese enzyme ferment

Shio-koji is rice inoculated with Aspergillus oryzae (the same culture used for sake, miso, soy sauce) mixed with salt and water. Over 7-10 days at room temperature, the koji enzymes hydrolyze rice starch into sugar and (more importantly for us) hydrolyze proteins into free glutamate — the N1 umami amplifier in our master formula.

Chemistry function
F4 enzymatic ferment · liberates N1 free-Glu via PMR7 (drying-as-umami-amplifier rule)
Used in
V1 (40g) · V5 (80g, the koji-max variant) · V2 (40g)
Halal status
✅ Yes — no alcohol byproduct (koji is enzymatic, not yeast-fermentation)
Why we make ourselves
Fresh shio-koji has 2-3× enzyme activity vs 30-day retail jar. V5 needs 80g per batch — retail cost RM 14/batch vs homemade RM 2/batch (7× savings)
Yield
~450g per batch (good for ~6-10 V1 batches OR 5 V5 batches)

§ 02 · INGREDIENTS3 ingredients · all halal

The only critical ingredient is the rice koji (kome-koji). Quality of the koji = quality of the shio-koji. Buy from a verified Japanese-brand source, not generic "fermentation starter".

Rice koji (米麹 kome-koji)
200g · the live ingredient
Verified Shopee MY sources (2026-05-17):
· Marukura Foods Japanese Dried Rice Koji 500g (direct from Japan) — gold standard, 500g lasts 2-3 batches
· Isesou Miyako Rice Koji (200g/500g/1kg) — handmade low-temp dried
Alternate searches: Shopee MY · rice koji · Lazada MY
Sea salt (coarse, non-iodized)
60g · 13-15% of total weight ratio
Avoid iodized salt — iodine can interfere with enzyme activity slightly. Coarse non-iodized sea salt is ideal.
· Available at any supermarket (Cold Storage, Village Grocer, Mercato)
Filtered or distilled water
300ml · room temperature
Avoid chlorinated tap water (chlorine inhibits koji enzymes). Boil + cool tap water or use filtered/bottled water.
Kome-koji quality check before buying Real kome-koji = rice grains with visible white-grey mycelium (fuzz). Should smell sweet + earthy, NOT sour or fermented-already. If it smells like alcohol — it's been over-fermented. Pass.
DO NOT confuse with these (halal kill-zones)
  • Shio-koji with mirin added — some commercial shio-koji has mirin (alcohol) — verify ingredient label
  • "Koji rice" sold as a finished product — that's not raw koji, it's already cooked rice
  • Mold inoculant kits not labeled Aspergillus oryzae — could be other species

§ 03 · EQUIPMENTWide-mouth glass jar + cloth + spoon — that's it

1L wide-mouth glass jar
Shopee MY · glass jar 1L wide-mouth · IKEA Korken 1L is gold standard · RM 8-15
Cheesecloth or breathable cotton
Shopee MY · cheesecloth · for breathable cover · RM 5-10
Rubber band or string
To secure cloth over jar mouth — any kitchen rubber band
Wooden / plastic spoon
For stirring — NOT metal (metal can inhibit some enzyme activity over time)
Kitchen scale (0.1g)
For salt + koji ratio · Shopee MY · digital scale 0.1g · RM 35-75

§ 04 · DAY-BY-DAYThe 7-10 day procedure

Active time is ~15 min on day 1, then ~2 min per day of stirring. The koji enzymes do all the work — your job is to keep the environment right (room temp, breathable cover, daily stir).

Day 1 Mix + start ferment 15 min

Sanitize 1L glass jar with boiling water, let dry completely (any moisture = mold risk).

Weigh 200g rice koji into the jar. Break up clumps with fingers (clean hands, washed with soap).

Add 60g sea salt directly to the jar. Stir thoroughly so salt is distributed evenly through the koji.

Slowly pour 300ml room-temp filtered water over the koji + salt mix. Stir well with wooden spoon. The mixture should look like a thick rice porridge.

Cover the jar mouth with cheesecloth, secure with rubber band. DO NOT seal airtight — koji needs to breathe.

Place in a stable room-temperature spot (20-25°C) away from direct sunlight. Kitchen shelf or pantry works well.

Mixture is uniform, no dry koji pockets, no excess water pooling on top. Salt fully dissolved into the koji-water mix.
If room temperature is >28°C in tropical conditions — store in a cooler indoor room (air-con room is fine). Above 30°C accelerates fermentation past the sweet spot and risks off-flavors.
Day 2-3 Daily stir + observe 2 min

Once per day (morning is consistent), uncover and stir vigorously with a clean wooden spoon for 30 seconds. Re-cover.

By end of day 2-3, you'll notice: aroma shifting from raw rice to slightly sweet · the koji grains starting to soften · liquid slightly creamier.

No mold growth on surface (mold = furry/colored spots — NOT the white fuzz on koji grains, which is fine). Aroma should be sweet/koji-like, NOT sour or alcoholic.
If you see colored mold (green, black, pink) — discard the batch and restart. This is rare if equipment is clean and salt ratio is correct.
Day 4-5 First taste-test (usable from here) 2 min + taste

Continue daily stir. By day 4-5, koji grains have softened significantly, mixture is creamier.

Taste a small spoonful (it's safe to eat — salt content is too high for pathogens). Should taste: salty first, then sweet/savory umami undertone.

If you need shio-koji urgently for a Friday trial, day 4-5 is usable — but it's still developing. The full umami punch arrives day 7-10.

Salty-sweet on the palate. Aroma sweet, slightly fruity, koji-rich. Texture creamy with softened rice grains.
Day 7-10 Peak — bottle + refrigerate 10 min

By day 7-10, the koji grains have mostly dissolved into a creamy paste. Aroma is full, deep, sweet-savory.

Taste-test: salty front + lingering Glu-rich umami back. If you taste mostly "salt", give it another 2-3 days at room temp.

When happy with flavor: transfer to a clean glass jar, seal airtight, and refrigerate. Fermentation slows dramatically below 5°C.

Smooth creamy paste, koji grains 80%+ dissolved, deep sweet-savory aroma. Tastes like a slightly-fruity miso paste at this stage.

§ 05 · TROUBLESHOOTINGCommon issues + fixes

Colored mold on surface (green, black, pink) Discard the batch. This means contamination during day-1 mixing. Restart with sanitized equipment + cleaner technique. The white mycelium fuzz already on koji grains is FINE — colored mold patches forming after day 2 are NOT.
Smells alcoholic / vinegary by day 4 Room too hot (likely >28°C). Fermentation went past sweet spot into yeast/acetic phase. Salvageable for some applications but flavor profile is different — use it for marinade base only, not for the V1/V5 master formula. Next batch: move to cooler spot or run in air-con room.
Mixture too dry, no liquid pooling Add 30ml filtered water + stir well. Koji absorbed more water than expected. Should be visibly creamy by day 3.
Mixture too watery, looks like rice soup Add another 20g rice koji. The salt-water-koji ratio is slightly off. Will normalize as koji softens.
Tastes only salty by day 7 Let it go another 3-4 days. Koji activity varies by source — Japanese-direct koji is usually more active than store-shelf brands. Sometimes day 12-14 hits peak.

§ 06 · STORAGERefrigerator life + usage notes

Refrigerated shelf life
3-6 months at 4°C in airtight glass jar. Enzymes slowly continue working — flavor deepens over time.
Freezer storage
Up to 12 months. Freezing halts enzyme activity. Thaw in fridge 24h before use.
When to discard
If smell turns acrid/sour (pH dropped — bad acid bacteria took over) or if visible colored mold appears.
Rotating batches
Run 2 jars in parallel — start a new batch every Monday so you always have peak-quality (day 5-10) shio-koji available for trial days.
Pro tip · aging for V5 KOJI-MAX For V5, use shio-koji aged 14-21 days — extra time deepens the koji-sake-soy character that defines the V5 umami profile. Keep one jar dedicated to V5 use only, started 2 weeks before each V5 trial.

§ 07 · HOW TO USEIn the V1/V5/V2 master formula

V1 BALANCED
40g shio-koji per 200g rehydrated hericium substrate (step 6 marinade)
V5 KOJI-MAX
80g shio-koji — the doubled-koji signature. Use aged 14-21 day batch.
V2 TEMPEH-MAX
40g shio-koji + 40g miso (V2 combines both koji ferments)
Other applications
1-2 tsp shio-koji per portion as standalone marinade (chicken substitute, tofu, fish substitute). Tenderizing power: 30 min at room temp = 2 hours of regular marinade.

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