Bring the water to a boil in a large saucepan. Put the rice in the boiling water. Immediately set to the lowest setting and simmer for 4 hours, preferably longer. It has to be a thick paste.
The pot should be big enough (5 liters) because the rice sometimes foams.
Due to the long cooking time, it is more worthwhile to cook the congee in larger quantities in advance.
In Asia this rice porridge is eaten with other side dishes for breakfast.