white mushrooms, button mushrooms, supermarket mushrooms
The mushrooms you most commonly see in the supermarket are cultivated white mushrooms. Their caps range in diameter from 1/2 to 3 inches, but it is only the smallest specimens that are labelled "button mushrooms."
White mushrooms have a mild, earthy flavor. Though their flavor is pleasantly subtle—almost bland—when raw, it deepens nicely as they are cooked. These mushrooms are available year-round but are at their peak in fall and winter.
Cremini mushrooms are a more flavorful version the white button, and the two can be used relatively interchangeably.
Seek out firm, unblemished, and uniformly colored mushrooms with tightly closed caps. You can tell a mushroom is past its prime when all of its gills are showing.
Trimming white button mushrooms is simple. All you really need to do is trim the very ends of the stems.
To wash or not to wash? There are different schools of thought on how to clean mushrooms. One approach is to brush them off with a dry or damp towel or a soft brush. This method works well if the mushrooms aren’t very dirty, but if they are, we prefer to wash them, albeit gently. Rinse them briefly, one at a time, under running water, then transfer them to a dry towel and give them a little pat to blot away surface moisture. This method removes the grime without completely soaking them.
Mushrooms tend to exude lots of moisture when they’re heated, particularly if they’ve been rinsed. This is why we like to sauté them, in plenty of oil or butter, over medium-high to high heat—the high temperature helps the moisture evaporate quickly so the mushrooms can then brown well.
White button mushrooms should be stored in a place that allows as much cool air to circulate around them as possible. Ideally, they should be arranged on a tray in a single layer, covered with a damp paper towel and refrigerated. Stored this way, they'll keep for up to 3 days.