How much does a cup of rice weigh?
A cup of rice can vary in weight for a few reasons. The type of grain and whether it's cooked or not is the biggest factor. First of all, a cup is a unit of volume rather than weight. A cup of raw, uncooked, rice will weigh about 180 grams. A cup of cooked rice, that's been boiled or steamed, will weigh about 200 grams. Why this is interesting is when you look at factors such as calorie count for each cup. A cup of raw rice has about 685 calories whereas a cup of cooked rice has 240 calories. The reason the calorie count breaks down like this is rice expands greatly when it's cooked. There are fewer grains of rice in a cup of cooked rice than raw. So the calorie count drops tremendously. The reason it cooked rice weighs more even though there is less rice overall, is because it now contains a substantial amount of water.
How to cook rice - the right way!
Cooking rice isn't hard. The problem is, most people don't know what they are doing. My advice would be to buy a rice cooker. They can be picked up for under $10 and work wonders. They take out a lot of the stress of cooking, they even keep the rice warm for you so it can be eaten throughout the day.
When it comes to preparing the rice, the biggest mistake people make is not washing the rice. Rice is full of starch and proteins that you don't want. By soaking the rice in cold water and beating it around a bit, you can get most of this starch out. Pour out the starchy water and refill the bowl of rice with cold water again. Repeat the process once more, this time the water should look less milky. The next mistake people make is messing up their ratios. A safe ratio is 2 cups of water to 1 cup of rice. This will ensure that your rice is soft and fluffy. Any less it will be dry, any more and it will be soggy. A teaspoon of salt shouldn't be plenty.
Cooking the rice is easy enough in a rice cooker, just press start. On a stovetop in a saucepan, it's best to bring the water to a boil and then turn the heat down low and put the cover on. 10-15 minutes should be enough, then turn the stovetop off. Leave the rice to rest, the steam will take care of the rest.
Why is rice so commonplace?
Rice can be found in many different people's cuisines. For a good reason, too. Rice is very easy to grow. At least, it's very sturdy. Rice paddies can be made pretty much anywhere. They are very easy to tend, too. There are even certain species of rice that can be grown in saltwater. Since it is so resilient and easy to grow it makes the perfect crop for most people. Then, you must consider how long-lasting rice can be. It stores incredibly well, back in the old days that was what mattered most. Food was very valuable, any spoilt food was a big deal. Rice can be stored in sacks and jars and will last for years if it's kept dry and away from pests. Luckily, rice is also a great source of energy. As food sources go, rice is one of the best.