The text that follows is from http://busycooks.about.com/library/lessons/blricesci.htm and was written by Linda Larsen. It has been shortened, corrected, and reformatted to make it easier to read, use, and find a permanent home in our archives.
How many times have you put a pot of rice on to simmer, and come back to it 20 minutes later to find a sticky, gluey mass of rice? Learn about the different types of rice, and what happens inside the grains during different cooking methods.
There are many different varieties of rice. They differ in amounts of nutrition and, more importantly, the type of starch. There are two types of starch in rice: amylose and amylopectin. Amylose is a long, straight starch molecule that does not gelatinize during cooking (think of making gelatin), so rice which contains more of this starch tends to cook fluffy, with separate grains. Long grain white rice has the most amylose and the least amylopectin, so it tends to be the fluffiest and least sticky. Amylose also hardens more when cool, joining tightly together and forming crystals that melt when the rice is reheated. Rice that is high in amylose has a lower Glycemic Index number (a GOOD thing!).
Amylopectin is a highly branched molecule that makes the rice sticky when it's released from the grain during cooking. Medium grain rice has more amylopectin, making it a good candidate for risottos, salads and rice pudding, which are served cold. And short grain rice has even more amylopectin and little to no amylose, so it's used most often for Asian cooking, when you want grains to be sticky so they are easier to eat with chopsticks. Then there's glutinous rice, which is very sticky when cooked, with the highest amount of amylopectin and no amylose.
White rice has the hull and bran removed, diminishing its nutritional content. But in the U.S., rice is generally enriched, with nutrients like calcium, riboflavin, iron, and niacin added. Brown rice has just the hull removed, so it has more fiber and nutrition. And wild rice is not a grain, but a seed of a grass native to North America.
Long Grain White Rice: Cooks up fluffy and separate. Less fiber, but usually enriched with nutrients, vitamins and minerals.
Medium Grain Rice: More amylopectin in the grains and a softer outer layer, so it releases starch during cooking and cooks up creamy.
Short Grain Rice: More amylopectin in the grains; releases lots of starch during cooking; sticky and creamy when cooked.
Brown Rice: Only the hull is removed during processing; the bran is retained, resulting in more fiber and nutrients. Takes longer to cook than white rice because the outer layer is harder.
Basmati Rice: Long grain rice, aromatic (smells like popcorn when cooking), cooks up fluffy and separate.
Wehani Rice: Long grain, unpolished brown rice, with a very sweet flavor. Cooks up fluffy and separate.
Jasmine Rice: Long grain and aromatic, but with more amylopectin than regular long grain rice, so it cooks up creamier than long grain.
Arborio Rice: Short grain rice usually used for risotto. It releases lots of amylopectin during cooking, so the finished dish is creamy and has a great soft mouth-feel.
Wild Rice: The seed of a native grass, this 'rice' takes longer to cook than brown rice and has a nutty flavor and chewy texture. It cooks up fluffy and separate, unless you cook it until it 'pops', or the outer covering disintegrates. Then the rice is softer and less separate.
Converted Rice: This is rice that has been partially precooked, then dried, so it cooks more quickly. It's a good choice if you aren't picky about your rice quality; you are also guaranteed consistent results. Instant Rice is even more processed; you just rehydrate it by adding it to hot water and letting it stand, covered, until tender.
Long grain rice cooks up most separate and fluffy if the grains are sautéed in a small bit of oil or butter until some of the grains start to look slightly translucent. Then add cold water (not hot) in the ratio of 1-1/2 cups liquid to 1 cup of rice. Bring the mixture to a boil, then cover tightly, reduce the heat, and simmer for 15 minutes, until the liquid is absorbed. Keep the cover on the pan, remove the pan from the heat, and let the rice stand for another 15 minutes to steam. Then fluff the rice with a fork.
You can cook rice in the microwave oven. Combine 1 cup rice with 1-3/4 cups liquid, a pinch of salt, and a tablespoon of butter in a 2 quart microwave safe baking pan. Cover the pan and cook on high for 5 minutes until the liquid boils. Reduce the setting to medium, or 50% power, and cook for 15-20 minutes (longer for parboiled rice) until liquid is absorbed. Fluff with fork. Brown rice should be cooked using the same technique, but cooking on medium for 30 minutes.
Brown rice is best cooked in more water, then drained if necessary when it's tender. Cover it generously with cold water or other liquid, then cover and bring to a boil. Reduce heat and simmer for 35-40 minutes, or until rice is tender when you bite into it. If there is any liquid left over, drain it off. Then return the pan to very low heat and cook for 2-3 minutes, fluffing occasionally with a fork, to slightly steam the grains.
Basmati rice, if you can find true basmati, is really a treat. Many recipes call for rinsing or soaking the rice before cooking to rinse off surface starch, but I agree with America's Test Kitchen, in that un-soaked and un-rinsed rice has more flavor and better consistency. Sauté the rice in a bit of vegetable oil, then add water in the same ratio for long grain rice, then bring to a boil, reduce heat, cover, and simmer for 17-18 minutes. Remove pan from heat and let stand to steam 10 minutes longer.
Risotto is a special method of cooking rice. Short or medium grain rice is first sautéed in oil or butter, then boiling liquid is added gradually, while stirring the mixture very frequently. This stirring helps loosen the outer surface of the rice, allowing more starch (amylopectin) to leak out into the sauce, making a creamy and rich dish. The rice is cooked until it's still firm but tender. I have made risotto with long grain white rice, with good success, so you can certainly use that rice if you prefer.
Sticky rice, or short grain or glutinous rice, is pretty easy to cook because it will naturally turn out sticky if cooked according to package directions. The challenge is to cook rice so the grains are tender and fluffy; sticky and creamy is easy!
Rice cookers are nice appliances that turn out whatever type of rice you like with no skill on your part whatsoever! If you cook a lot of rice, consider buying a rice cooker.