Potatoes are grown all around the world, making them one of the world's most important vegetables. The potato may have its roots in ancient Peru but today it is grown in more than 80 countries. Originally thought to be poisonous, this underground tuber became a staple food in Ireland until failure of the crop led to widespread famine and massive emigration in the 1840's. Potatoes, when prepared with little additional fat, are low in calories and a good source of vitamins, minerals and fiber.

Potatoes in America can be categorized as russets, long whites, round whites and round reds.

• Russets are popular for baking and for French fries. They are large (often up to 18 ounces each) and oval in shape with rough brown skin and starchy flesh. Russet Burbank, also referred to as Idaho or russet, is the leading variety.
• Long whites are an all-purpose potato with thin pale brown skin. They average about eight ounces each. They can be baked, boiled or fried.
• Round whites are good for boiling and mashing. Smaller than long whites with a light tan skin, they are similar to round red potatoes.
• Round reds have a smooth red skin, and because of their lower starch and higher moisture content, they are good for boiling and mashing.
• A number of specialty varieties are becoming available in some supermarkets and farmers' markets. Yukon gold potatoes, with a skin and flesh that ranges from yellow to buttery gold, have a rich moist texture that is ideal for mashing. Blue potatoes have a delicate flavor with blue to purple skin and flesh.
• New potatoes are freshly dug young potatoes. They may be any variety, but most often are round reds. New potatoes can be as small as marbles or almost as large as full-size potatoes, but they should have a very thin wispy skin. The sugar in these young potatoes has not completely converted to starch so they have a crisp, waxy texture.

Fresh potatoes are commercially grown in 48 states in overlapping growing seasons, so at least one or two varieties are always available. Potatoes in many forms are also available frozen, refrigerated, dehydrated and canned.

Select potatoes based on their intended use. Choose potatoes that are clean, firm, smooth, well-shaped and free from sprouts. Any "eyes" should be minimal and shallow. Skins should be dry and without wrinkles or cracks. Avoid potatoes with green-tinged skins or black spots.

1 pound potatoes = 2 to 3 medium; 3-1/2 cups cooked, sliced or chopped; 2 to 3 cups mashed.

Store potatoes in a cool, dry dark location (light and warmth encourage sprouting) for up to two weeks. They may be stored in a paper or burlap bag. Check them occasionally and remove any potatoes that have sprouted or begun to shrivel. One rotten potato can spoil the whole lot. Avoid storing potatoes and onions together as the gases given off by the onions can cause the potatoes to spoil more quickly. Avoid storing potatoes in the refrigerator as the starch turns to sugar making them overly sweet. New potatoes, if not used within in a few days, should be refrigerated.

Scrub potatoes before cooking with a vegetable brush to remove embedded dirt. For many uses, potatoes do not need to be peeled. When peeling, use a swivel-bladed vegetable peeler rather than a knife. The skin and the flesh below the skin are rich in vitamins, so peel away as little of the flesh as possible. Cut out the "eyes" and any blemishes. A green-tinged flesh is an indication that the potato has been exposed to sunlight. Trim away any green skin or flesh, because it can be toxic in large amounts. Peeled potatoes should be immediately covered with water as the surface discolors quickly. Sliced or cut-up potatoes speed up cooking. Pieces of similar thickness ensure even cooking. Before baking or microwaving potatoes, pierce the skin with a fork to allow steam to escape and prevent them from exploding.