Blanching improves vegetable quality, impacting the appearance, taste and texture of the finished dish. Whether it's brightening the color of greens, reducing soil-borne microorganisms on tubers or minimizing vitamin loss in inflorescence varieties, blanching provides different benefits to different vegetables. A host of secondary benefits go along with blanching, too, like reduced cooking time and easy skin removal. Red potatoes, for example, have thin skin and waxy flesh, making them one of the hardest varieties to peel dry. Take a few minutes to blanch them, though, and you can peel them without even using a knife.
Scrub the potatoes under cool running water with a vegetables brush to remove all dirt and debris and bring a pot of water to a rolling boil on the stove. Fill a large bowl half full of ice and add just enough water to cover.
Add the potatoes to the boiling water. Blanch the potatoes for three to five minutes according to size -- three minutes for small potatoes and up to five minutes for large potatoes.
Drain the potatoes and place them in the bowl of ice water. Let the potatoes sit until they're cool enough to handle, about 30 seconds, then remove. Cool three or four potatoes at a time, then empty the bowl and add fresh ice water.
Hold a potato in a cotton kitchen towel and rub vigorously all over, using friction to remove the skin, if you need to peel the potatoes.
Scrap or peel away any remaining flecks of skin with a paring knife. Cut out any eyes or discolored portions from the flesh. Store the potatoes in an airtight food-storage container in the refrigerator until you use them.
You can use the basic blanching technique to prepare french fries for frying. Cut them into fries and boil them for about 15 minutes instead of five minutes.
You can adapt the basic blanching technique to any vegetable.
If blanching potatoes for freezing, drain them after blanching and allow them to dry. Cut the potatoes in pieces, if desired, and pack them in an airtight food-storage bag, leaving 1/2-inch of headspace, and seal. Store the potatoes up to one year in the freezer.
Steam-blanching and microwave-blanching aren't recommended for most vegetables, including red potatoes. Water-blanching provides the most even heat distribution.
Time the blanching period for best results. Overblanching causes heat to penetrate too deeply, and, when combined with the rapid cooling in the ice bath, alters the structure of the starch and creates a mealy consistency.