How to Cook Japanese Rice: Washing, Soaking, Ratios, and Resting

Before you start: what variety you are cooking matters

This guide applies to Japanese short-grain rice — koshihikari and similar varieties (akitakomachi, hitomebore, domestic Calrose). These are high-amylopectin grains designed to be sticky, cohesive, and slightly sweet. Medium-grain rice behaves similarly but with slightly less stickiness. Long-grain jasmine or basmati follows different ratios entirely and is not covered here.

If you are unsure which variety to use or which Japanese rice labels mean what, the full variety context is at Rice. If you are cooking in a rice cooker and want to know what else the machine can do, see Rice Cooker Meals.

Step 1: Wash the rice until the water runs nearly clear

Place the measured rice in a bowl or the rice cooker bowl. Add cold water, agitate gently with your hand for 10 seconds, then pour off the cloudy water. Repeat three to four times. The goal is water that runs mostly clear — not perfectly transparent, but no longer milky white. Do not scrub or grind the grains; rinse and pour.

The starch washed off is surface starch that would otherwise produce a gluey, heavy texture in the finished rice. Washing does not remove the starch inside the grain — only the excess on the outside. Cold water slows starch absorption during washing, which is why warm water is avoided in this step.

How many rinses: Three rinses handle most rice. Fresh-harvest shinmai rice (typically sold in autumn and early winter) may need four. The water never becomes perfectly clear; some cloudiness is normal and fine.

Step 2: Soak for 30 minutes before cooking

After washing, cover the rice with the measured cooking water and let it soak for 30 minutes at room temperature. Do not drain the soaking water — cook in it. The soak allows the grain to absorb water evenly before heat is applied, which produces more uniform texture across the whole batch: no hard centers, no mushy outside.

In winter or with cold tap water, extend the soak to 45 minutes. In summer with warm water, 20 minutes is often sufficient. Soaking for longer than 60 minutes at room temperature is not beneficial and can produce a slightly sour smell in hot weather.

Most Japanese rice cookers have a built-in soak phase in their white rice cycle — if yours does, you can add water and press start without a manual soak. Check your cooker's manual to confirm.

Step 3: Use the right water ratio

The standard water ratio for Japanese short-grain rice in a rice cooker is 1 part rice to 1.1 parts water by volume, or 1:1.0 by weight (rice absorbs more water by volume than by weight). Most rice cooker cups (180 ml) have fill lines marked on the inner pot for this ratio.

Adjust the ratio in these situations:

• Shinmai (new-harvest rice, autumn): reduce water by 5–10% — the grain has higher natural moisture content
• Older grain (stored over a year): increase water by 5% — the grain has dried out more in storage
• Stovetop in a heavy pot: use 1:1.2 — stovetop loses more steam than a sealed rice cooker
• Sushi rice: reduce water slightly (1:1.0 by volume) because the rice vinegar seasoning adds liquid after cooking

Measuring by weight is more accurate than by cup. Rice shrinks and settles differently depending on age and how it was poured, which makes volume measurement variable. A kitchen scale eliminates that variable.

Step 4: Cook — rice cooker or stovetop

Rice cooker method

Add washed, soaked rice and measured water to the rice cooker bowl. Select the white rice setting. Press start. The machine manages the soak phase (if it has one), the boil, the steam, and the switch to warm automatically. Do not open the lid during cooking.

Reference cooker: Zojirushi NP-HCC10 Induction Heating Rice Cooker (affiliate link — we may earn a commission at no extra cost to you). IH models produce more even heat across the full cooking cycle, which matters especially for the steam phase. A conventional microcomputer cooker in the same brand's lineup handles daily rice well at lower cost.

If your question is about which rice cooker to buy: see Japanese Rice Cookers for a breakdown by use case and budget.

Stovetop method (heavy-bottomed pot)

Use a heavy-bottomed pot with a tight-fitting lid. Add washed, soaked rice and water (1:1.2 ratio for stovetop). Bring to a boil over medium heat uncovered, then immediately reduce to the lowest possible simmer and cover. Cook 12 minutes. Remove from heat and leave covered for 10 minutes. Do not lift the lid during cooking or resting — steam loss disrupts the texture.

The stovetop method produces excellent rice with practice, but requires more attention to heat level than a rice cooker. A cast iron or enameled pot holds heat most consistently.

Step 5: Rest covered for 10 minutes after cooking

When the rice cooker switches to warm (or the stovetop rest timer is up), leave the lid on for 10 minutes before serving. Do not skip this step. The rest period allows steam still trapped between the grains to redistribute evenly — the top layer firms up, the bottom layer relaxes, and the whole batch reaches consistent texture from top to bottom.

Opening the lid immediately causes the top layer to flatten and dry slightly from the escaping steam, while the bottom may still be slightly wet. The 10-minute rest is not a safety step; it is a texture step.

Step 6: Fold, do not stir

When the rest is complete, open the lid and fold the rice with a rice paddle (shamoji) or a silicone spatula using a gentle cutting and folding motion — not stirring. Cut down through the rice vertically, turn a section over, and rotate the bowl. Repeat until the grains are loosened and any steam pocket at the bottom is released. This aerates the rice slightly and separates any grains that have stuck together, without mashing or breaking them.

Serve immediately or leave on warm for up to 1 hour. For storage, see How to Store Cooked Rice. For reheating without drying the grain out, see How to Reheat Rice.

Common problems and what causes them

• Mushy, gluey texture: too much water, insufficient washing, or no soak. Reduce water by 5–10% and add a full wash cycle next batch.
• Hard centers or dry texture: too little water, or lid opened during cooking. Check your ratio and resist opening the cooker.
• Uneven texture (soft on outside, hard inside): skipped soak. The soak phase is what allows water to penetrate the center of the grain before heat gelatinizes the surface.
• Rice sticking to the bottom of the pot: normal on stovetop at the very bottom layer; excessive sticking indicates heat too high or ratio too dry. A thin crispy layer (okoge) at the very base is considered a feature in some Japanese cooking — but if more than one layer is sticking, lower the heat.
• Rice too sticky to separate: variety issue (some Calrose and akitakomachi are stickier than koshihikari) or excess surface starch from insufficient washing. Add one more rinse cycle.

If the troubleshooting points to a variety mismatch — or you are unsure which grain you are working with: see Japanese Rice Varieties. For what to do with rice once it is cooked — storage, reheating, or turning it into a one-pot dish — see Rice Cooker Meals.

Where to go next

For the full context on rice — variety differences, the role of amylopectin, and what to look for when buying Japanese rice — start at the Rice hub. For what to do with leftover rice, see the Leftover Rice Guide. For one-pot variations using the same rice cooker logic — takikomi gohan, okayu, shio koji rice — see Rice Cooker Meals. For the equipment question, see Japanese Rice Cookers.