Updated: Sep 29, 2021
What can I tell you about Japanese rice that you don't already know? You'll know that rice is the staple food of Japan, is short grained and is rather sticky when cooked.
You might also know that traditionally, rice has deep cultural and religious connections to Japanese people (the Emperor performs a rice planting ceremony every year) but that over the years, the consumption of rice has fallen steeply (about 50% in the past 50 years) as eating habits change and younger Japanese eat more Western style foods.
But did you know that the Japanese still get through about 60kgs of rice per person per year which is about 10 times the average Brit? Or that there are over 4,000 varieties of Japanese rice? (OK, maybe you don't need to know that!) Anyway, here's a primer giving a few facts about Japanese rice that should come in handy...first off, let's look at what kinds of rice are used in Japan.
There are 4 general types of Japanese rice as follows:
Japanese white rice (Hakumai)
Hakumai is the most common rice in Japan and what you'll almost certainly be given in a Japanese restaurant. Hakumai is milled and polished meaning that the hull, rice bran and rice germ are all removed, leaving the carbohydrate rich endosperm. White rice gets something of a bad rap these days from those pointing out that polishing removes fibre ad trace minerals and vitamins from the rice. On the positive side, rice has no cholesterol, gluten or extrinsic sugar, virtually no fat and allergic reactions to rice are almost unknown (have you ever met anyone with a rice allergy?). While there are lots of varieties available in Japan, the most common varieties are Koshihikari and Sasanishiki. A recent innovation in Japan has been the introduction of no-wash
rice (musenmai) which over the last couple of decades has taken around 20% of the market. You'd be forgiven for thinking that removing the chore of washing rice was the reason for this development but in fact it was driven by ecology - Japanese researchers discovered that the milky coloured water washed down millions of sinks in Japan after rinsing white rice was one of the primary causes of pollution and algal bloom in Japan's waterways and lakes. Chances are, if you buy Japanese rice outside of Japan, it won't be musenmai so you will need to wash it. If you want to earn some eco-points, the simple solution is to put the water used to wash the rice on your flowers beds (your flowers will thank you for it!). Some Japanese and Koreans use rice water as a facial cleanser - you can find lots about this on the web.
Japanese glutinous rice (Mochigome)
Mochigome is the second most common variety of Japanese rice. Mochigome grains are very short, more opaque and, when cooked, much stickier than Hakumai. As the scientifically minded among you will know, carbohydrate is usually composed of two forms of starch, amylose and amylopectin - amylopectin gives rice its stickiness and the starch in mochigome is almost 100% amylopectin (Basmati, on the other hand, is far higher in amylose, so it is not at all sticky). Like other rice varieties, mochigome is gluten free. Mochigome is used in many traditional Japanese dishes such as red rice (Sekihan) and is also used to make traditional Japanese sweet foods. (incidentally, you might see Mochigome advertised as "sweet rice" - this doesn't mean it has a sweet flavour however as it doesn't contain sugar but Mochigome is used to make mochi cakes.) Mochi-gome is pounded into a thick paste to make mochi cakes. Mochi even hit the news in the UK earlier this year as a health hazard. (see here if you missed this interesting piece of reporting).
Japanese brown rice (Genmai)
Genmai is essentially hakumai with its overcoat left on. The milling of genmai leaves all of the grain intact and the bran coat and only the hull is removed. Unlike hakumai, genmai is lauded for its health benefits, including the retention of more vitamin B and fibre (genmai is about 2% fibre compared to 0.3% for hakumai) from the retained bran coat - on the other hand, genmai is more difficult to digest and some people experience tummy upsets when they eat it. Genmai needs to be rested in water for 1 - 2 hours after washing and before cooking to let the grains absorb more water through the tough bran coat. There aren't really any recipes in Japanese that exclusively call for genmai as opposed to hakumai and if you ask any Japanese what most comes to mind when you say the word genmai, they may well think of genmaicha which is tea made with green tea and roasted brown rice. If you want to try genmai, have a look at my short tutorial here on how to cook it in a saucepan - apart from the health benefits, you might find you prefer its flavour and texture over white rice for some dishes.
Japanese germinated brown rice (Hatsugamai)
As the name suggests, germinated brown rice is brown rice that has germinated. It is
claimed that this improves the flavour and the texture and also releases higher levels of nutrient from the grain, in particular gamma-aminobutyric acid (from which the name GABA for this type of rice arises). There are some big claims made for germinated brown rice such as its curative properties for hypertension and insomnia. Whatever else the process does, it certainly softens the bran layer, making the rice much easier to digest. If you'd like to watch my video tutorial on hatsugamai made by the Japanese producer Fancl, you can find it here.
Japanese semi-milled rice (Haigamai)
Also called "germ rice", (haiga means germ), haigamai sits between hakumai and genmai in the milling process - the hull and bran are removed but the germ is left intact. The germ is essentially the rice embryo - what would develop into a plant - so it is relatively high in vitamins and other trace elements.
Washing Japanese rice
Trawling through all the articles about this subject on the internet, you could be forgiven for thinking that washing Japanese rice is a dark art known only to ninja cooks and that there is a right and a wrong way to do it. When i was at school in Japan, our home economics teacher
old us to rinse Japanese rice only once - that way you minimise the loss of nutrients. These days, most commentators advise washing white rice 2 or 3 times, until the water runs clear. IMO, neither way is right, but then neither way is wrong either. Washing once removes any foreign bodies that might be in the rice and retains more of the starch in the rice. Washing 2 -3 times removes more of the starch - so in a way, it comes down to what you want from your rice - if you want stickier rice, limit the washing, if you prefer your rice less sticky, rinse more.
Washing brown rice is a lot simpler - you can wash it 2 -3 times because all the nutrients are safe behind the bran coat and won't be washed away - take a look at the photo on the left - as you can see, the water runs clear even on the first rinse because the rice is unpolished. Some commentators say you should "work" brown rice in water to soften the bran but I've never found this makes much difference - brown rice does however need to be left for at least an hour in water, so that the bran can soften before cooking.
Storing Japanese rice
When rice is harvested, it has a moisture content of around 20%. The drying process reduces moisture content to around 14%. Genmai has more retained moisture, in the form of oil left in bran coat than polished white rice - so it is more prone to moisture loss. General advice about storing rice is pretty much common sense - store it in an airtight container and consume it within 2 - 3 months. The older rice becomes, the dryer it gets and its aroma fades. It will need a little more water when it is cooked. If you buy Japanese rice in bags, it can be kept in the bag unopened for at least a year or more.