Among the 40,000 types of rice available, there are definite distinctions of colour, flavour, fragrance and texture. All rice falls into three main categories: long-grain, medium-grain and short-grain. When cooked, long-grain rice is light and fluffy and its grains stay separate. It's used for pilaf, biryani and with curries. White rice is washed, de-husked and polished to remove the bran, which removes healthy fibre and some nutrients. Brown rice has the bran intact, so needs longer to cook and gives it a nutty flavour. Red rice is also a nutty variety. Fragrant rices include soft jasmine (used in south-east Asian dishes) and the more robust basmati (Middle Eastern and Indian dishes).
Short- and medium-grain rice is pudgy when cooked, moist, and more or less sticky. Its pearlescent, polished grains are used in Japanese dishes; it's sticky enough to pick up with chopsticks. For risotto, starchy arborio is often used. It can absorb up to five times its weight in liquid (long-grain generally absorbs three times its weight) and produces a creamy texture. The Veronese prefer Vialone nano, a ''semi-fino'' (stubby) grain that produces the characteristic wave texture when served from pan to plate. The Piedmontese swear by ''superfino'' carnaroli - longer and thinner and used in more ''elegant'' risottos (such as seafood and saffron). For paella, calasparra absorbs the requisite liquid but stays more separate than risotto rice. For an old-school English-style pud, use short-grain white rice.
Glutinous rice is named for its sticky texture. A particular strain of long-grain rice, it goes against the grain of long-grains, which are typically separate, not sticky. It's used widely throughout Asia, in sweet and savoury dishes. Many recipes recommend it be soaked - anywhere from a few hours to overnight. And here's the kicker: it is cooked with steam - on a piece of cheesecloth or, traditionally, in a conical woven basket. (No wonder it's not in everybody's everyday rice repertoire.) It comes in pearly white, which becomes translucent and shiny when cooked; and in black. You can avoid trying to steam-cook glutinous rice by making a sweet, sticky black rice pudding loaded with palm-sugar shavings, which is deep purple, slightly chewy and sticky - and great with coconut cream.
Technically a grass seed, wild rice has been grown commercially only as recently as the mid-1970s (commercial crops of rice have been traded for centuries) in North America and Hungary. It's a low-yield crop with finicky growing conditions (an even level of water throughout its life, for example), so it's costly by comparison (about $5 for 150 grams). It has a smoky, nutty signature and is often mixed with basmati rice - to add flavour and keep the cost down. Cooking it straight requires a 1:3 rice-to-water ratio, and anywhere between 35-50 minutes. When it's cooked, wild rice bursts open to reveal paler flesh. You can also pop it, as you would popcorn (but with just a smidgen of oil); it's crisp and crunchy and makes a great topping for muesli or dessert.
Rice doesn't puff easily. It lacks the requisite hard outer case (such as that of corn), so it needs to be pressurised and heated until it expands. Some processes actually use ''puffing guns'', which shoot out the puffed rice. Other processes mix rice flour and water that is extruded from a nozzle - and made to look like a puffy rice grain. The high temperature required to expand rice can deplete its nutritional value, although some commercial varieties add vitamins. Whole brown rice grain puffs are also available. Most popular at breakfast, either mixed with other cereals or straight, their fragile, crisp ''skins'' collapse on contact with milk - that's the popping sound. The almost chalky puffs might be lightweight in the flavour stakes but have a thrilling texture.