Electronic Rice Cooker

Hi friends...

How the electronic rice cooker automatically turns off when the cooking process is completed?

Thanks to all.....

I'm pretty sure it's just a timer. You could test this by putting some water in and time when it shuts off. The time will only be close each time, not exact, unless there's a microcontroller involved.

Like upandatthem say should be on timer.

upand_at_them said:

I'm pretty sure it's just a timer. You could test this by putting some water in and time when it shuts off. The time will only be close each time, not exact, unless there's a microcontroller involved.

Click to expand...

Hi friend...
Thank you for your response.....

How timer can known, the cooking process is completed within the fixed time?
I mean, the time for completion of the cooking is varying depending on the rice quantity.

Its rice, there is no some algorythm and calc, just rice and heat. I supose they test and practical determine needed time for cooking rice in that volumen (capacity) of that cooker.

You should spent more time in kitchen. :smile:

Unfortunately, as subbuindia suggested a timer could not function as expected as the quantity of rice and water are both widely variable.

Actually, I believe it is a temperature sensor held in close contact with the removable rice pan using a spring.

Once the temperature begins to rise sharply above the approximate boiling point of water, the temperature of the heating elements is reduced to a warming cycle.

The temperature of the pan cannot exceed the approximate boiling point of water as long as water in the liquid state remains in the pan.

The actual trigger temperature would depend on factors such as altitude and solutes (rice particles) in solution.

However a sharp continuing increase in temperature would indicate no water in liquid form remains, this phenomenon is demonstrated in the following video.


BigDog

Very nice video, really amazing.

I agree with BigDog. That's how I've seen them work. The control lags the process just enough to result in the bottom being slightly scorched.

tpetar said:

Very nice video, really amazing.

Click to expand...

Yes. A vivid demonstration of the relevant laws of physical chemistry.

As long as water remains in the cup in liquid form the cup temperature cannot exceed the boiling point of water.

Notice the cup begins to burn, ignition temperature, above the water line.

I've actually used this technique while in the wilderness without pots and pans.

BigDog

https://en.wikipedia.org/wiki/Rice_cooker

Basic principle of operation (basic rice cooker models)

The bowl in the rice cooker is usually removable; beneath it there is a heater and thermostat. A spring pushes the thermostat against the bottom of the bowl for good thermal contact. During cooking the rice/water mixture is heated at full power. The water reaches a temperature of 100 °C (212 °F); it cannot get hotter than its boiling point. By the end of cooking there will be no free water left; most will have been absorbed by the rice, and some boiled off. As heating continues, the temperature can now rise above boiling point; this makes the thermostat trip. Some cookers switch to low-power "warming" mode, keeping the rice at a safe temperature of approximately 65 °C (150 °F); simpler models switch off.


Cooking rice with an electric rice cooker

The rice is measured and added to the inner bowl or washed in a separate bowl (it is not recommended to wash rice in the inner bowl itself) in order to remove loosened starch and residual bran. Strainers are often used in the washing and draining process. For better texture and taste, some types of rice, e.g. Japanese rice or Calrose rice which is suited for absorption method, require pre-cooking water absorption. The water absorption step typically involves letting the rice stand for at least 5 min after draining water from the washing step and soaking the rice in the measured water for at least 15 min (or some claim it to be 1 hour) before cooking. The water draining step is believed[by whom?] to make the water measurement more accurate, if the water is measured and added after the initial water absorption that takes place in the washing step. Some people prefer to achieve the water absorption by simply leaving the rice soaking in the rice cooker overnight before starting cooking in the morning. Some other types of rice, e.g. long-grain rice or scented rice such as jasmine rice, do not require washing or the water absorption step. The water for cooking is added to the inner bowl by using measuring cups or simply filling up to the appropriate graduated mark in the inner bowl. Although cold water is normally added, boiling water is used for cooking sushi rice.

Different kinds of rice require different amounts of water. Usually, there are graduated marks for the right amount of water only for white rice, but sometimes there are separate scales for brown rice (as more water is required) or for cooking other food in the appliance.

Once the lid is closed and the cooking cycle has been activated, the rice cooker does the rest. Most models give a countdown in minutes to the "ready time," or beep when done. After cooking cycle is completed, it is recommended that the rice is to "rest" for 5 minute for post-absorption and then to be stirred to prevent the grains from clinging to each other too hard. Some rice, e.g. long-grain or scented rice, do not seem to require this post-absorption step.

Some higher-end models automatically time the soaking (pre-cooking water absorption) and the resting periods, therefore, there is no need to manually manage the water absorption or time these steps.

tpetar said:

The bowl in the rice cooker is usually removable; beneath it there is a heater and thermostat. A spring pushes the thermostat against the bottom of the bowl for good thermal contact. During cooking the rice/water mixture is heated at full power. The water reaches a temperature of 100 °C (212 °F); it cannot get hotter than its boiling point. By the end of cooking there will be no free water left; most will have been absorbed by the rice, and some boiled off. As heating continues, the temperature can now rise above boiling point; this makes the thermostat trip. Some cookers switch to low-power "warming" mode, keeping the rice at a safe temperature of approximately 65 °C (150 °F); simpler models switch off.

Click to expand...

What do you know? I was correct.

I guess all those semesters of Chem, P. Chem and O. Chem pay off from time to time.


BigDog

You are guru with reason.