Slow cookers operate by bringing up the temperature of food over several hours before reaching a simmering point. Their big advantage is that you can toss in chicken, rice, vegetables and maybe a can of mushroom soup in the morning, and when you get home from work, the meal is done. Precooking rice isn't necessary, but opinions will vary on technique.
Rice and water amounts
The ratio of rice to water doesn't need to change when using a slow cooker. The standard for cooking long grain white rice is to use 474 ml (2 cups) of water to 200 g (1 cup) of rice. Brown rice will require an extra 60 to 120 ml (1/4 to 1/2 cup) of water. Because of the tight fitting lid, slow cookers will not evaporate a significant amount of moisture even over a long cooking time. Because of the length of time a slow cooker takes to reach a simmering temperature, raw rice will need to cook for at least three hours on a low setting in order to cook fully. On a high setting rice, will cook in about two hours, although this can vary according to the individual slow cooker.
Slow cookers are fairly low tech devices and don't need a lot of fussing, but there are a couple of things you can do to help your cooker along. When cooking rice, grease the sides of the liner with either oil or butter. It's unlikely the rice will burn if you are using the proper amount of water; but this will help keep the rice from sticking and make clean-up much easier. Rinse your rice before placing it in the cooker. This will help remove starch from the grain which can make the rice sticky. Don't lift the lid. Once your cooker is going, let it go. Because of the length of time it takes to heat, you stand to lose up to 20 minutes of cooking time every time you lift the lid. Wait until towards the end of a 2-hour cooking period before checking on the rice. But don't panic if you still see lots of water and hard rice. Remember that it will take the slow cooker about two hours to even reach a simmering point, the temperature needed to start cooking the rice. Slow cookers are best used for just that; long, slow cooking of stews and soups. If you're concerned about time, you may be better off using a rice cooker or cooking rice on the hob.
Slow cooker rice recipe
Get used to cooking rice in a slow cooker with a simple chicken and rice recipe. Rinse 2 to 4 pieces of raw chicken and place in the slow cooker. Add 400 g (2 cups) of rice, 600 ml (2 1/2 cups) of broth and a can of mushroom soup. Stir the ingredients and turn the pot on high for one hour and then down to the low setting for 7 to 8 hours. You can add celery, potatoes or carrots as well to this recipe.