Rice cooker - Suihanki

Japanese: 炊飯器 - すいはんき

A device for cooking rice. The character "kasigyo" is a combination of the characters for fire and sui (an abbreviation of the character for blowing), and means "to cook (kasigyo)" ( until the Muromachi period). In other words, it means to cook rice by blowing on it to make a fire and boiling or steaming rice or wheat. The etymology clearly shows how rice was cooked in the past, but pots were used exclusively as rice cookers. In the early modern period, pots with rims were used, and when charcoal or gas became the fuel, bunka pots and other pots came to be used. Electric rice cooking was invented around 1921 (Taisho 10), but the first ones were electric stoves with electric heaters attached to the stove, and those made in the early Showa period simply had a heater set inside the double pot. The electric rice cooker that cooks rice automatically just by turning on the switch was developed in 1955 (Showa 30). Its simplicity and convenience quickly made it popular, and gas rice cookers appeared two or three years later. Recently, rice cookers with various added functions, such as electronic rice cookers, timers, and built-in microcomputers, are available on the market.

[Masaki Eiko]

Electric rice cooker

They are also called electric kettles. They are broadly divided into two types according to the heating method.

(1) Direct heating type (hot plate type): A sheathed heater is cast into an aluminum casting to create a hot plate, and the bottom of the inner pot is placed on top of it to directly cook the rice by conductive heat. This is efficient, but the rice tends to be hard at the top and soft at the bottom.

(2) Indirect air heating (kamado style): A circular sheathed heater is attached to the space between the inner pot and the inner frame, and the rice is cooked by being enveloped in the radiant heat of the heater and the surrounding air heated to a high temperature. The top and bottom are cooked evenly. It is also called kamado-style cooking because it applies the principle that in a kamado, the flames spread from the bottom to the sides of the pot, heating the entire pot, resulting in fluffy, evenly cooked rice. In both types, a heat sensor is built into the part that comes into contact with the bottom of the inner pot, and when the moisture in the inner pot runs out and the temperature of the bottom of the pot rises, the heat sensor detects the temperature change and switches off.

[Masaki Eiko]

Electric rice cooker with electronic jar

This is an electric rice cooker with the function of an electronic rice cooker added. Since its release in 1972, demand has increased year by year, and it has become the mainstream of rice cookers today. It has the same cooking function as an electric rice cooker, but it has a heater attached to the body and inner lid, the body is filled with insulating material (glass wool), and a temperature controller built in to keep the temperature of the cooked rice constant. Semiconductors such as thermistors or magnetic thermostats called thermal reed switches are used for temperature control. Those with a second cooking or reheating process have a dedicated timer that automatically reheats the rice on low heat after cooking is finished to remove excess moisture and allow the rice to steam sufficiently. There are also pressure types that increase the pressure during cooking to cook the rice. Those with a timer will automatically switch on if you set the cooking time. Those with a built-in microcomputer will automatically control the heat level appropriate to the amount of rice to be cooked when the time is set, and cook the rice by absorbing water, cooking the rice, second cooking, and keeping it warm.

[Masaki Eiko]

Gas rice cooker

It consists of a stove and a pot, most of which are removable. When the rice is done, an automatic extinguishing device detects the temperature change at the bottom of the inner pot and turns off the main burner. Rice cooked with gas is similar to a kamado style stove, and there is less uneven cooking. There are also models with an electric jar that cooks rice with gas and keeps it warm with electricity, and models with a timer.

According to the JIS (Japanese Industrial Standards), the temperature of rice after 12 hours of keeping warm should be within the range of 71°C plus or minus 6°C, and there should be no unpleasant odor or browning. To enjoy it to the fullest, avoid keeping it warm for long periods of time, and if the amount is small, do not keep the rice warm as it will dry out and become hard.

[Masaki Eiko]

[Reference] | Hot pot | Rice

Electric rice cooker (electric kettle) from the early Showa period
The aluminum pot has a double bottom and a heating wire built in. There is no automatic switch. ©Shogakukan ">

Electric rice cooker (electric kettle) from the early Showa period

Source: Shogakukan Encyclopedia Nipponica About Encyclopedia Nipponica Information | Legend

Japanese:

炊飯用の器具。炊の字は火と欠（吹(すい)の省略形）の2字をあわせてできたもので、「炊(かし)ぐ（室町時代まではかしく）」の意。つまり、息を吹いて火を燃やし、米や麦などを煮たり蒸したりして飯をつくることをいう。語源が昔の飯炊(た)きのさまを如実に示しているが、炊飯器としてはもっぱら鍋(なべ)が使用されていた。近世になって、つばのある羽釜(はがま)が用いられ、燃料が炭やガスになると文化鍋なども使われるようになった。電気での炊飯は1921年（大正10）ころから考案されていたが、当初のものはかまどに電熱器を取り付けた電気かまどであり、昭和初期につくられたものも二重釜の内部にヒーターをセットしたにすぎなかった。スイッチを入れるだけで自動的に炊き上がる電気炊飯器の開発は、1955年（昭和30）である。その手軽さ、便利さが受けてたちまち普及し、2、3年後にはガス炊飯器も登場した。最近は電子ジャー付き、タイマー付き、マイクロコンピュータ内蔵などさまざまな機能を付加したものが出回っている。

［正木英子］

電気炊飯器

電気釜ともいう。加熱方式によって2種類に大別される。

(1)直接加熱式（熱板式）　アルミニウム鋳物にシーズヒーターを鋳込んで熱板とし、その上に内鍋の底部を密着させて伝導熱により直接炊き上げる方式。効率はよいが、上部の飯は固めで下部が柔らかめになる傾向がある。

(2)空気間接加熱式（かまど式）　円形状のシーズヒーターを内鍋と内枠の空間に取り付け、ヒーターの放射熱と高温に加熱された周りの空気とにより包み込むように炊き上げる方式。上下が均一にむらなく炊き上がる。かまど炊き風ともいわれるのは、かまどでは炎が釜の底から側面にまで回って釜全体が加熱されるため、飯がふっくらとむらなく炊き上がるという原理を応用したものだからである。いずれの方式も、内鍋の底と接触する部分に感熱体が組み込まれていて、内鍋の水分がなくなり鍋底の温度が上昇すると、感熱体が温度変化を感知してスイッチが切れる仕組みになっている。

［正木英子］

電子ジャー付き電気炊飯器

電気炊飯器に電子ジャーの機能を付加させたもの。1972年に発売されて以来年々需要が高まり、いまでは炊飯器の主流になっている。炊飯機能は電気炊飯器と同じだが、胴と内蓋(うちぶた)に保温ヒーターを取り付け、本体の周囲には断熱材（グラスウール）を充填(じゅうてん)し、さらに、炊いた飯の温度を一定に保つための温度コントローラーを内蔵している。温度制御にはサーミスターなどの半導体、または、サーマルリードスイッチというマグネット式のサーモスタットが使われている。二度炊きとか追い炊きの工程があるものは、炊飯終了後に余分な水分をとばして十分蒸らすため、自動的に弱火で再加熱する専用タイマーがついている。炊飯時に圧力をあげて炊き上げる圧力タイプのものもある。タイマー付きは炊飯時間をセットしておけば、自動的にスイッチが入る。マイクロコンピュータを内蔵したものは、予約時間になると炊飯量に適した火力で、吸水から炊飯、二度炊き、保温までを自動的にコントロールして炊き上げる。

［正木英子］