Thermos cooking has been used by campers and hikers for many years and is growing in suburban popularity. Using a thermos to cook rice, wheat and other grains simplifies the process. Since the preparation is the only step utilizing a heat source, cooking in a thermos is energy efficient. It also saves time because you aren't laboring over the stove, making sure the rice is cooked perfectly. Planning ahead is the key when cooking rice in a thermos, allowing enough time for the grains to absorb enough water and cook.

Heat water in a kettle until it boils.

Measure one part of rice to four parts of water. If your thermos holds 5 cups, this is 1 cup of rice to 4 cups of water.

Rinse the rice under cold water in a strainer. This cleans any residual dirt or debris left on the grains.

Pour your rice into the thermos. Add the four parts of boiling water.

Cover tightly and shake the contents, evenly distributing the water throughout the rice.

Let the rice sit for eight to 12 hours. Shaking it will let you know if there is any residual water that hasn't been absorbed, meaning the rice isn't done. Check hourly after eight hours. Open and check the consistency with a fork.