Rice Cooker: How It Works, the Measuring Cup, Rice Types and Care

How a rice cooker works

Simple rice cooker with a thermostat

Under the removable inner pot sits a heating plate with a spring-loaded temperature sensor in the middle. As long as there is water in the pot, the temperature at the bottom stays at the boiling point of about 100 degrees. Once the rice has absorbed the water, the bottom gets hotter. In classic machines a magnet then loses its hold, and the switch flips from cooking to keep-warm. The machine needs no clock for this.

Fuzzy logic

Machines with fuzzy logic control heat and time with a microprocessor and several sensors. They compensate for small differences in quantity, water and room temperature. Usually a soaking, a cooking and a resting phase run one after the other. A simple machine usually needs 20 to 30 minutes for two cups of white rice, a fuzzy logic machine with all phases often close to an hour.

Induction

In induction machines, often marked IH, a coil creates a magnetic field that heats the metal inner pot itself. The heat is generated in the pot material at the bottom and sides. The rice cooks more evenly, and the machine adjusts the temperature faster.

Pressure

Pressure rice cookers usually combine induction with a tightly sealing lid. Under pressure, water boils above 100 degrees. Brown rice and sticky rice turn soft faster, and white rice gets a softer, stickier texture. These machines sit at the top end of the price range.

The measuring cup and water lines

The cup that comes with the rice cooker holds 180 milliliters. That matches the Japanese measure gō (合) and about 150 grams of uncooked rice. A household cup holds more, usually 200 to 250 milliliters. If you use it instead of the cup, the water lines no longer fit, and the rice turns out too dry.

Inside the pot you find scales, often separate for white rice, sushi rice, brown rice and rice porridge. The number at the line stands for the number of cups of rice. For two cups, you fill water up to line 2 of the matching scale. Level the rice first so you can read the line cleanly.

Cooking rice in a rice cooker: step by step

1. Measure two level cups of rice, that is 360 milliliters or about 300 grams. That is enough as a side for three to four people.
2. Wash the rice in a bowl two to four times, until the water stays almost clear, and drain it in a sieve.
3. Put the rice in the inner pot, level it and add water up to line 2 of the matching scale.
4. Let Japanese rice soak for 20 to 30 minutes if your machine has no soaking program.
5. Dry the outside of the pot, insert it, close the lid and start the program.
6. After it switches to keep-warm, leave the lid closed for 10 to 15 minutes. Fuzzy logic machines often include this rest already.
7. Fluff the rice with the paddle from the bottom up so excess steam can escape.

Fresh from the rice cooker, the rice goes well with Gyudon or as the base for Onigiri.

Which rice types work in a rice cooker?

• White long-grain rice and jasmine rice: white rice scale, for jasmine slightly below it.
• Basmati: soak for 20 minutes, drain, and add a little less water than the line says.
• Japanese short-grain rice: sushi scale or white rice scale. For sushi rice, you season it afterwards with vinegar, sugar and salt.
• Brown rice and black rice: brown rice program and matching scale. Simple machines without this program often leave it too firm; add more water then and soak it for an hour beforehand.
• Sticky rice: with its own program or with clearly less water than for white rice. Steamed, it turns out more reliably, as described in How to cook sticky rice.
• Parboiled rice: works well, but needs more water than the white rice scale.

Many machines also have a program for rice porridge such as Khao Tom, and some come with a steamer insert for vegetables or dumplings.

What to look for when choosing

• Size: The figures refer to cups of 180 milliliters. A machine for 3 cups (0.54 liters) is enough for one to two people, 5.5 cups (1 liter) for two to four, 10 cups (1.8 liters) for larger families. A single cup of rice turns out worse in a big machine.
• Inner pot: A thick pot spreads the heat more evenly. A nonstick coating makes washing easier but needs gentle handling. Uncoated stainless steel lasts longer, but the rice sticks to the bottom more easily.
• Keep-warm function and timer: The keep-warm function holds the rice ready to serve for a few hours. With a timer you start in the morning and eat in the evening.
• Programs: White rice, brown rice, sushi, sticky rice, rice porridge and quick cook are common. Only pay for programs you will use.
• Heating technology: For occasional white rice a thermostat machine is enough. Fuzzy logic or induction pay off more if you cook rice every day or brown rice often.
• Cleaning: Look for a removable inner lid and a removable steam vent.

Care and cleaning

• Unplug the machine and let it cool down.
• Wash the inner pot by hand with a soft sponge. Abrasive cleaners and steel wool scratch the coating. It goes in the dishwasher only if the manual allows it.
• Use the plastic or wooden paddle that comes with the machine for stirring and serving, not a metal spoon.
• Take off the inner lid and steam vent after cooking and rinse them. Starch and smells collect there. Empty the condensation tray too.
• Wipe the heating plate and sensor with a damp cloth. A grain of rice between pot and plate disturbs the sensor.
• If the coating flakes off, order a replacement pot from the manufacturer.

Do not keep rice warm for many hours. It dries out, turns yellowish and smells musty. Cool leftovers quickly and put them in the fridge within about an hour.

Cooking rice without a rice cooker

A pot with a heavy bottom and a tight-fitting lid also makes good rice. You bring rice and water to a boil, turn the heat to the lowest setting, cook it covered and let it rest for 10 minutes. The steps are in How to cook rice, and the water amounts for each type in Rice types.

You steam sticky rice in a bamboo basket or a steamer insert over boiling water. In a pressure cooker, brown rice cooks faster than in an open pot; follow the times in the pot's manual. The rice cooker saves you attention: you do not have to stand by the stove, and the rice stays warm until everyone is at the table. If you only cook rice now and then, the pot is enough.