JPH05245037A - Rice cooking method - Google Patents

Abstract

PURPOSE:To avoid unevenness in cooked rice by concurrently energizing a plurality of electric heaters disposed at different positions under a pot which accommodates rice and water to cook rice until just before the boiling of water occurs and thereafter separately energizing said heaters. CONSTITUTION:A pot 6 is detachably inserted into a protection frame in a body of a rice cooker. At least two or more of electric heaters 7 for cooking rice are mounted to the underside of the pot 6 at different positions. In the figure, two heaters 7a, 7b are mounted concentrially. A predetermined amount of rice and water is put in the pot 6 and a power source is turned on to heat the pot 6. The heaters 7a, 7b are energized until just before the boiling of water occurs, but after the boiling, the heaters 7a, 7b are alternately energized to heat the rice until it is cooked. In the pot, upward flows turn around as illustrated by arrows so that uniform heating can be provided. As a result, uniform cooking can be achieved, thereby tasty rice can be provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rice cooking method using an electric rice cooker.

[0002]

2. Description of the Related Art Conventional electric rice cookers have an electric heater provided at the bottom of a pot, rice and water are contained in the pot, and the electric heater heats the pot to cook rice.

[0003]

However, in this electric rice cooker, the portion directly above the electric heater is heated strongly, but the other portions are heated to a low degree,
It is difficult to cook rice uniformly in the pan.

The process of cooking rice in a pan will be briefly described. First, in the initial stage of heating, water is heated and convection occurs in the water, and the convection also heats the rice while stirring with the water. The rice in the pan is heated almost uniformly.

Then, the water is boiled by heating and is vigorously stirred, but immediately before the boiling of the water, a part of the starch of the rice is eluted into the water to increase the viscosity of the water and Also swells and hinders the movement of individual rice grains.

By continuing heating, the viscosity of water further increases, the swelling of rice grains also progresses, and the heat evaporates the water to reduce the amount of water. Movement will not occur at all.

In this state, the water contained between the rice grains is heated to evaporate through the rice grains, and finally all the water evaporates to leave fully swollen rice, which is dried up. Then, the rice cooking is completed.

At the final stage of this rice cooking process, when the water contained between rice grains evaporates in the lower part of the pot, the steam escapes through the rice grains in the upper part, so that a steam passage is formed between the rice grains. Is formed, and the cooked rice has small holes that are commonly called crab holes.

Ideally cooked rice that is heated strongly from the bottom of the pan has crab holes all over its surface,
Each grain of rice absorbs water sufficiently to swell, and the water between the grains of rice has completely evaporated, and it becomes a delicious rice that is cooked up with a lustrous and fluffy texture. The presence of the crab hole on the surface of the rice serves as an indicator that the rice was cooked well.

However, in the conventional electric rice cooker as described above, the pan is not heated over the entire bottom surface, and only the portion where the electric heater is arranged is heated. Occurs.

Since strong heating is performed right above the electric heater, as described above, good cooking with crab holes can be obtained. However, in other parts,
It is only indirectly heated by convection of water heated directly above the electric heater, but the degree of heating is weak,
Also, in the final stage of cooking rice, the steam generated at the bottom does not pass between rice grains, so crab holes are not formed,
It is not possible to obtain a good meal.

[0012] Conventionally, in electric rice cookers, various measures have been taken in order to eliminate unevenness in heating and to uniformly heat the whole. However, none of them was satisfactory.

Particularly in Japan, electric wiring for household use is usually 1500 W, and since the wiring is shared by various electric appliances, it is difficult for only the electric rice cooker to use large electric power. Therefore, a typical electric rice cooker is usually 800 ~
Many are heated with electric power of about 1000W.

However, in the case of an electric heater of this degree, it is sufficient to heat and cook rice in a limited range immediately above the electric heater, and good cooked rice with a crab hole can be obtained. However, if the electric power is dispersed and heated all over the bottom of the pan, the amount of heat per unit area is insufficient and good cooking cannot be obtained. Therefore, even if it is heated uniformly from the bottom of the pan, good cooking results cannot be obtained by itself.

The present invention has been made in view of the above circumstances, and does not make the electric heater have an excessively large output,
It is an object of the present invention to provide a method for uniformly and satisfactorily cooking rice in a pan.

[0016]

According to the present invention, in a method of storing rice and water in a pan and heating the bottom of the pan to cook rice, different positions of the bottom of the pan are provided at the bottom of the pan. A plurality of electric heaters for heating are arranged, at least two or more of the electric heaters are simultaneously energized to heat the pot until just before boiling, and then the electric heaters are individually energized alternately and dried up. It is characterized by heating up to.

Further, in the present invention, the sum of the electric powers when the plurality of electric heaters are individually energized is larger than the rated power of the electric rice cooker, and when the electric heaters are energized at the same time, the individual electric heaters are individually heated. It is preferable to regulate the electric current flowing through to make the total power match the rated power.

[0018]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a rating of 1000 for cooking rice according to the present invention.
1 shows an example of a W electric rice cooker, which is a main body 1
And a lid 2 that closes the upper part of the main body 1. In the main body 1, an inner container 5 is fitted in an exterior body 3 via a heat insulating material 4, and a pot 6 is housed in the inner container 5.

An electric heater 7 is arranged in a double concentric circle below the bottom of the pot 6. As shown in FIG. 2 (a), the electric heater 7 has an outer electric heater 7a and an inner electric heater 7b which are separate from each other and can be individually energized.

These electric heaters 7a and 7b are shown in FIG.
As shown in (a), it is connected in parallel to a household power source 8 of AC100V, and switches 9a and 9b are connected to the electric heaters 7a and 7b, respectively.

Further, in this embodiment, as the electric heaters 7a and 7b, heating wires of 12.5Ω are used, and 100V is used.
When a voltage of 8 A is applied, a current of 8 A flows and heat of 800 W is generated. In the wiring, a triac 10 is connected to the household power source 8 and regulates the total amount of current flowing through the electrothermal heaters 7a and 7b to be 10 A or less of the rated current.

Then, a predetermined amount of rice and water are put in the pot 6, the pot 6 is housed in the inner container 5, and the electric heater 7 is energized to cook rice. FIG. 3B shows currents flowing through the electric heaters 7a and 7b in the process of cooking rice.

First, when the switches 9a and 9b are turned on, the electric heaters 7a and 7b are energized. However, since the total amount of the current at this time is regulated to 10 A or less by the triac 10, the electric heaters 7a and 7b are not connected to each other. 5A each is distributed, and each heats up as a heater of 500W. As a result, the electric rice cooker heats the contents 11 with a total rated power of 1000W.

Thus, the contents 11 in the pot 6 are heated and immediately before the start of boiling, the electric heaters 7a and 7b are alternately and individually energized. In FIG. 3B, the switch 9b is turned off, and first, only the electric heater 7a is energized. The electric current at this time is 8 A, and the electric heater 7a fully generates heat to concentrate and heat the portion of the pot 6 near the outer periphery of the bottom surface.

As for the convection state of the contents 11 in the pot 6 at this time, as shown in FIG. 2 (b), the peripheral portion of the pot 6 is strongly heated to generate an upward flow, and the central portion is heated. As a result, a downward flow occurs.

After maintaining this state for a predetermined time, the switch 9
When a is turned off and the switch 9b is turned on, the electric heater 7a at the outer peripheral portion is de-energized, and the electric heater 7b at the central portion is energized. The electric current at this time is also 8 A, and the electrothermal heater 7b heats up fully to heat the central portion of the pot 6 in a concentrated manner.

The convection state of water in the pot 6 at this time is shown in FIG.
As shown in (c), contrary to the above, the vicinity of the central portion of the pan 6 is strongly heated to generate an upward flow, and the vicinity of the outer peripheral portion is heated to a low degree, so a downward flow is generated.

Then, the switches 9a and 9b are switched at predetermined time intervals to alternately energize the electric heater 7a and the electric heater 7b, so that the peripheral portion of the pot 6 and the central portion thereof are alternately switched.
Each is heated intensively.

When the rice in the pot 6 is sufficiently cooked and the water is evaporated to dry up, the switches 9a and 9b are turned to O.
Set to FF, the electric heaters 7a and 7b are de-energized, the heating is stopped and the rice is steamed.

FIG. 4 shows another embodiment of the electric rice cooker for cooking rice according to the method of the present invention. As shown in FIG. 4 (a), the bottom portion of the pot 6 is divided into halves, each of which is divided into halves. The electric heaters 7a and 7b are arranged in the range of.

Similarly, in this embodiment, the electric heaters 7a and 7b are simultaneously energized in the initial stage of rice cooking, and when boiling is reached, the electric heaters 7a and 7b are alternately energized to heat and dry. Bring up.

When the electric heater 7a on the left side of the drawing is energized, the left half of the pot 6 is heated strongly as shown in FIG. 4 (b), causing an upward flow in the contents 11 and at the right half. Is not heated, a downward flow occurs in the content 11. When the electric heater 7b on the right side of the drawing is energized, conversely, as shown in FIG. 4 (c), an upflow is generated in the right half and a downflow is generated in the left half.

The electric heaters 7a and 7b according to the present invention
It does not mean that the electric heaters 7 other than the electric heater 7 to be energized should not be energized at all in the step of energizing each of them individually, and a small amount of electric power that does not impair the operation of the present invention is energized. It is possible.

For example, in FIG. 3B, when the electric heater 7a in the outer peripheral portion is energized, the electric heater 7b in the central portion is not energized, but the electric heater 7b in the central portion is also electrified. 100-2, which is much smaller
It is possible to energize with a power of about 00 W, and vice versa.

Electric heaters 7a, 7 to be energized in this way
By supplying a small amount of electric power to the electric heaters 7b and 7a other than b, it is possible to prevent the temperature of the contents of the portion apart from the electric heaters 7a and 7b to be originally energized from locally lowering, The convection path of the contents is complicated and unstable, and the rice can be cooked more uniformly throughout the whole.

In the above embodiments, the two electric heaters 7 are provided, but three or more electric heaters 7 may be provided. In this case, at least just two or more electric heaters 7 are energized by heating until just before boiling, and not all of the electric heaters 7 are energized. In the step of individually energizing the electric heaters 7, some of the electric heaters 7 are energized and the other of the electric heaters 7 are not energized. Therefore, the number of energized electric heaters 7 is not always required. It is not limited to one.

[0038]

In the present invention, a plurality of electric heaters 7a, 7b are provided at the bottom of the pot 6 for heating different positions of the pot 6.
Are placed, and the electric heaters 7a and 7b are simultaneously energized to heat strongly and bring to a boil rapidly.

After the contents 11 of the pot 6 have boiled, the electric heaters 7a and 7b are alternately energized, so that the contents 11 immediately above the energized electric heater 7 are strongly heated and energized. The contents 11 in the vicinity of the electric heater 7 not being heated are indirectly heated by the convection of the contents 11.

In the conventional electric rice cooker, even if the whole is uniformly heated, some heating unevenness is unavoidable, and there is a strong heating portion and a relatively weak heating portion. Occurs. Since this state continues throughout the entire course of cooking rice, in the portion where the heat of the electric heater 7 is difficult to be transferred, the convection generated from the strongly heated portion always causes the indirect heating, and the direct heating is performed. Insufficient heating occurs because it is not done.

However, in the present invention, since a plurality of electric heaters 7a and 7b are switched and alternately heated, a portion where heating is insufficient at one time is switched at another time by switching the electric heaters 7a and 7b. It is strongly heated by the nearby electric heater 7 and is sufficiently heated throughout.

Further, in the conventional electric rice cooker, since only a fixed part is heated at all times, the electric heater 7 is used in a state where the viscosity of the contents 11 increases and the swelling of rice grains progresses and the fluidity becomes poor. An upflow is continuously generated at a specific position near to, and only a downflow is generated at a position away from.

Then, at the location where the upflow occurs, the strong upflow pushes away the rice grains and the upflow path is fixed, and the upflow continues steadily along a certain path. Therefore, only a specific portion along the route is strongly heated, and there is a tendency to locally overcook.

However, in the present invention, even at a portion where an upflow is generated at a certain time, the upflow is lost when the electric heaters 7a and 7b are switched, and the path of the upflow that has been generated once disappears. Therefore, when the electric heaters 7a and 7b are switched again, a new path is created for the upflow, but that path is newly created at a location different from the previously created path.
Do not overcook locally.

According to the second aspect of the invention, the total electric power when the electric heaters 7a and 7b are individually energized is larger than the rated power of the electric rice cooker, and the electric heaters 7a and 7b are individually energized. In this case, since the range directly heated by the electric heaters 7a and 7b is small, the narrow range is strongly heated with a large electric power close to the rated electric power.

Since the range to be heated is switched one after another, the pot 6 will be heated strongly at any place in the whole range of the pot 6, even temporarily. As a result, the cooked rice has crab holes all over the surface, and a very good cooked rice can be obtained.

[0047]

Therefore, according to the present invention, the rice is cooked uniformly over the whole, and the effect that the unevenness of cooking is not caused is produced.

Conventionally, in order to eliminate the uneven cooking, it was intended to heat the pot 6 as evenly as possible, but in the present invention, only part of the pot 6 is intentionally heated non-uniformly. By switching the heating location over time, uneven cooking was eliminated and rice was successfully cooked over the whole area.

According to the second aspect of the invention, when heating part of the pot 6, the power density per unit area is increased,
By heating locally, without exceeding the rated power of the entire electric rice cooker, and switching the heating range one after another, the same rice cooking result as heating over the entire rated power. It is possible to cook delicious rice with crab holes over the entire surface.

[Brief description of drawings]

FIG. 1 is a central longitudinal sectional view showing an embodiment of an electric rice cooker embodying the present invention.

2 (a) is a plan view showing the arrangement of electric heaters with respect to the pan in the embodiment of FIG. 1, and FIG. 2 (b) and (c).
FIG. 4 is a central longitudinal sectional view showing a convection state of the content liquid when the two electric heaters are individually energized.

3 (a) is a wiring diagram of the electric heater shown in FIG. 1, and FIG. 3 (b) shows a time-course program for energizing two electric heaters.

FIG. 4A is a plan view showing another embodiment of the arrangement of the electric heater with respect to the pot, and FIGS. 4B and 4C are convection states of the content liquid when the two electric heaters are individually energized. It is a central longitudinal cross-sectional view showing.

[Explanation of symbols]

 6 pans 7a, 7b electric heater

Claims (2)

[Claims] 1. A method of storing rice and water in a pan and heating from the bottom of the pan to cook rice, wherein a plurality of electric heaters for heating different positions on the bottom of the pan are arranged at the bottom of the pan. , Characterized in that at least two or more of the plurality of electric heaters are simultaneously energized to heat the pot until just before boiling, and then the electric heaters are individually energized alternately to heat up to dry-up. Cooking method 2. The sum of the electric power when individually energizing the plurality of electric heaters is set to be larger than the rated power of the electric rice cooker, and when the electric heaters are simultaneously energized, the current flowing through each electric heater is The rice cooking method according to claim 1, characterized in that the total power is regulated to match the rated power.