Japanese Rice.
Japanese rice-cooker manuals say soak thirty minutes in summer and two hours in winter. The difference is the temperature of the tap water.
Rice (ご飯, which also means "meal") is the centre of the Japanese table. The grain is japonica (XXI.2): short, plump, low in amylose, cooking moist and slightly sticky so it can be lifted with chopsticks. Washing (研ぐ, "polishing") removes loose starch and the remains of bran from the surface; done briskly in three or four changes of water until it runs nearly clear, it gives grains that stay distinct and taste clean. Modern rice is milled more cleanly than old rice, so it needs gentler washing than the vigorous scrubbing of older cookbooks.
Soaking (浸水) lets water diffuse to the centre of each grain before it cooks; grains turn from translucent to opaque white as they absorb about a quarter of their weight. Unsoaked rice cooks with a hard core and soft surface. The rate of uptake rises with temperature, so soaking takes about 30 minutes in warm summer water and up to 2 hours in cold winter water. Then the rice is cooked with about 1.1–1.2 times its weight of fresh water in total, counting what it has soaked up — boiled hard, simmered covered about 12 minutes, then left 10–15 minutes off the heat with the lid on to finish by steam (XXI.3). The workshop soaks rice.
Below: the water absorbed by short-grain rice soaked for the minutes you choose in water at the temperature you choose (teaching first-order uptake, about 30 % at saturation, rate doubling every 10 °C), with the ready point, and how much water to add for 300 g of rice after draining.
- Wash rice properly.
- Soak for the water temperature.
- Cook and steam Japanese rice.
- Adjust water for soaked rice.
Wash, soak by the season, cook, steam
In the teaching model rice is soaked through after about 26 minutes in summer water at 28 °C, 45 at 20 °C and 103 in winter water at 8 °C — the rice-cooker makers' advice, explained. Soaked rice has already taken up a quarter of its weight, so less water goes in the pot: for 300 g, about 360 g of water in total, less what it has absorbed. Rice cookers soak automatically, warming the water first.
Method for 300 g (2 合, about 4 bowls): wash in a bowl with cold water, swirling briskly and draining quickly the first time (the rice absorbs the first water fastest), 3–4 changes until nearly clear. Soak by the season, drain 10 minutes in a sieve. Put in a heavy pot with 290 g water (after a 30-minute summer soak), cover, bring to a boil over high heat, turn to low and cook 12 minutes, then off the heat 10–15 minutes without lifting the lid. Fluff with a wet paddle, cutting and turning (天地返し). Keep cooked rice warm above 60 °C or cool it quickly; never leave it at room temperature for hours (XII.4).
Cook two small pots of rice, one soaked 30 minutes and one not soaked at all. Bite grains from each: is there a hard core?
Terms
- 研ぐ
- Washing rice briskly in several changes of water.
- 浸水
- Soaking until the grains are opaque through.
- 合
- Gō: about 180 mL of raw rice.
- 蒸らし
- Resting covered off the heat to finish by steam.
Sources
- S. Tsuji, Japanese Cooking: A Simple Art, Kodansha, 1980 (rev. 2006).
- A teaching value chosen for the course: the right order of magnitude and shape, not a measurement of a particular food.
- Rice amylose classes used by rice breeders (IRRI; B. O. Juliano, Rice Chemistry and Technology, 3rd ed., 2003): waxy (glutinous) 0–2 %, very low 3–9 %, low 10–19 % (most japonica and jasmine), intermediate 20–25 % (many basmati), high above 25 % (many long-grain indica); higher amylose cooks drier, fluffier and firmer and hardens faster when cold.