Yellow miso
Dry soybeans to koji to salt by weight, about 11.5% salt.
Koji, Miso & Soy · Calculator
Koji Miso Salt Calculator
Enter your dry soybeans and pick a miso style to get the koji, salt, crock size and ageing time for a homemade batch.
Live calculator · updates as you type
Your miso
Miso styleI weigh inRice koji; the all-purpose miso. Salt is a percentage of the finished paste. Weigh the soybeans dry; they roughly double after soaking and cooking. Koji is weighed as bought, fresh or dried.
Your batch
Koji 1.00 kg
Salt in the paste 416 g
Cooked soybeans (approx.)2.20 kg
Salt for the surface36 g
Finished miso3.62 kg
Crock size3.9 L · 4.2 qt
Age for3–6 months
Salt level Standard salt for a long, safe age
What to do next
Make this miso in 4 steps
For 1.00 kg of dry soybeans.
Free printable
Keep this batch on one page
A batch card made from your numbers, to save as a PDF or receive by email:
- Your koji and salt in big type
- These steps with tick-boxes
- Packing and tasting dates
- A log as the miso ages
Per 1 kg dry soybeans (about 2.2 kg cooked)
| Style | Koji | Salt and ageing |
|---|---|---|
| Sweet white | 2000 g | 268 g (6%) · 4–8 weeks |
| Yellow | 1000 g | 416 g (11.5%) · 3–6 months |
| Red | 800 g | 429 g (12.5%) · 6–18 months |
| Barley | 1000 g | 396 g (11%) · 6–12 months |
Ratios that age safely
The right salt for every miso
Salt decides how long miso can age and how it tastes when it is done. The calculator gives the koji and salt for your beans; the guide below covers styles, packing and what is normal on the surface.
Use these reference values to interpret your results
- 1 : 1 : 0.42
- ~6% salt
Sweet white
Twice the koji, a quarter of the age: ready in 4–8 weeks.
- 12–13%
Long-aged red
Enough salt to age safely for a year or more.
Miso salt formula
Salt = % ÷ (100 − %) × (cooked soybeans + koji)Salt is a percentage of the finished paste. Cooked soybeans weigh about 2.2 times their dry weight; koji is weighed as bought. Sprinkle about 1% extra salt on the surface before sealing.
Understand and use your results
Choose a miso style, then enter the weight of your soybeans before soaking. The style sets the koji ratio and a standard salt level; you can change the salt percentage within a safe range.
The calculator returns the koji and salt to buy, the salt to sprinkle on the surface, the finished weight of the batch, the crock size and how long to age it.
Worked example
1 kg dry soybeans, yellow miso, 11.5% saltCooked soybeans ≈ 2.2 kg; koji 1 kgSalt = 11.5 ÷ 88.5 × 3.2 kg ≈ 416 g; about 3.6 kg misoSalt and koji by miso style
More koji and less salt give a sweet miso that is ready fast; less koji and more salt give a deep miso that needs time.
Sweet white2 × koji, 5–7% salt, 4–8 weeks warm.
Yellow1 × koji, 11–12% salt, 3–6 months.
Barley1 × barley koji, about 11% salt, 6–12 months.
Red0.6–0.8 × koji, 12–13% salt, 6–18 months or more.
Why the salt level matters
Miso ages at room temperature for months, and salt is what lets the koji enzymes and salt-tolerant yeasts and lactic acid bacteria work while keeping spoilage organisms out. Long-aged miso below about 10% salt is the common cause of sour, off-smelling batches. Low-salt white miso is safe because it is short-aged and then refrigerated.
Packing the crock
Form the paste into fist-sized balls and throw them into the crock to drive out air, pressing each layer down. Smooth the top, sprinkle the surface salt, cover the paste with plastic wrap pressed onto the surface, and weigh it down with about 20–30% of the miso weight. Store somewhere cool and dark.
What grows on top
A dark liquid (tamari) pooling on top is normal and good; stir it back in or save it. A thin white film is usually kahm yeast and can be scraped off. Fuzzy, coloured mould on the surface is removed with a generous margin; the salty paste beneath is normally fine. Pink, slimy or rotten-smelling miso throughout should be discarded.
FAQ
Miso Salt Calculator questions
How much salt do I put in homemade miso?
It depends on the style. Sweet white miso uses about 5–7% salt and is ready in weeks; yellow and barley miso use about 11–12%; red miso 12–13% for a long age. The percentage is of the finished paste: cooked soybeans, koji and salt together.
What is the ratio of soybeans to koji to salt?
A classic yellow miso is 1 kg dry soybeans, 1 kg rice koji and about 420–450 g salt. Sweet white miso doubles the koji and cuts the salt to around 270 g; red miso uses less koji and a little more salt.
Can I use less salt in miso?
Only for short-aged miso. Salt is what keeps spoilage organisms out over months of ageing. Below about 10%, age it for weeks rather than months, keep it cool, and refrigerate it once it tastes ready.
How long does homemade miso take?
Sweet white miso: 4–8 weeks in a warm room. Yellow: 3–6 months. Barley: 6–12 months. Red: 6–18 months or longer. Taste from the middle of the crock and stop when you like it.
Does it matter if my koji is dried?
Weigh it as bought. Dried and fresh rice koji are used by similar weight in home recipes; if using dried koji, mix it with a little of the soybean cooking liquid first so it is not too stiff.
Koji and miso guides
Calculators and guides for your next step.
- How to make miso Calculator · Soak, cook, mash, mix and pack: the full method.
- Types of miso Calculator · White, yellow, red, barley and soybean miso compared.
- How to make koji Calculator · Grow your own rice koji for miso.
- Fermentation brine calculator Calculator · Salt for vegetable ferments and brines.
