Cooking old-fashioned oatmeal in the microwave takes just a few minutes, depending on the type of oats and your preferences for texture. Although the author Samuel Johnson dismissed oats in his 1755 "A Dictionary of the English Language" as "a grain which in England is generally given to horses," oatmeal is growing in popularity. According to a 2015 article at SpecialtyFood.com, more Americans reported eating cold cereal than hot cereal, but sales of cold cereal declined from 2012 to 2014, while sales of hot cereal have continued to increase.
According to the Whole Grains Council, a nonprofit advocacy group, all rolled oats -- whether instant; quick; regular, also called old-fashioned; or thick-cut -- count as whole grains and include all parts of the oat kernel. All these forms come from oat groats, the whole kernel, which manufacturers steam and roll out into flakes so they cook more quickly. Instant and quick oats are rolled more thinly than old-fashioned or thick-cut varieties.
Ratio of Liquids to Oats
Generally speaking, old-fashioned oatmeal cooks with 1 part of oatmeal for each 2 parts of water. That said, if you like oatmeal on the more dense side, you might use a bit less than 1 cup of water, for example, for a half-cup of oatmeal. For oatmeal that is more creamy, use milk instead of water, but keep the ratio of liquid to oatmeal the same as for water.
Cooking Times and Temperatures
Old-fashioned oats cook in 2 to 3 minutes in the microwave. Times vary depending on your specific microwave and whether you like your oatmeal more or less dense. Shorter cooking times produce moister oatmeal; longer times, a more dense bowlful. It's a good idea to stir the oatmeal before serving it to make sure that it's evenly heated.
A dash of salt is optional in your morning cereal, and you won't miss it if you load up the bowl with other flavorful ingredients. A sprinkling of cinnamon and a small handful of raisins, dried cranberries or currants add both sweetness and warm flavor to the bowl. Or, choose fresh fruit, such as sliced bananas any time of year, and strawberries or blueberries in season. Keep a jar of chopped and toasted pecans, almond slices or walnuts on hand to give your oatmeal some crunch and protein.