Since oatmeal is a matter of personal preference—some people like a thick consistency while others like it a little soupy—you may have to play with the amount of oats or water to suit your taste. For me, I like it somewhere in between—not a gloppy gelatinous glue-like texture, but more on the thick side than the soupy side. I like it to be pourable but thick. When I make this recipe, I use steel-cut oats and 4 ½ cups of water.
Keep in mind, not all oats are created equal. There is a difference between steel-cut oats and regular rolled oats. Steel-cut oats (sometimes called Irish oats, Scotch oats, or coarse-cut oats) are whole grain groats (the inner portion of the oat kernel) that have been cut into only two or three pieces. Rolled oats, on the other hand, are traditionally oat groats that have been rolled into flat flakes.
Because of the textural differences, cooking times will vary between them—rolled oats need less cooking time than the steel-cut oats. The basic recipe provided here is for steel-cut oats. If you are using rolled oats, be sure that they are not quick cooking or instant, and reduce the cooking time from 8 hours to 4 hours using an automatic timer.
Source: How to Make Crockpot Oatmeal, Tipnut.com
4 cups water
1 cups steel-cut oats
¼ teaspoon salt
Fruit pieces (e.g., apples, blueberries, bananas, dried cranberries, figs, etc.)
Combine all ingredients in a slow cooker and turn on low heat. Cover with lid and cook for 8 hours. Add toppings and serve hot.