Both silverskin and pearl onions are small in size -- about one-half inch to just over 1 inch -- and may be difficult to differentiate. The pearl onion reveals a white, shiny pearly skin when peeled. Some people prefer the silverskin onion over the pearl onion because it takes more work to peel a pearl onion. The silverskin onion is a small bulb with no skin and has a silvery appearance.
Silverskin or pearl onions can be planted from seeds or from small bulbs either outdoors or indoors. Silverskin must be sown in the summer months and properly cultivated to form good-size bulbs by the end of the season. Pearl onions are ideal for gardens in cold climates, in the fall and winter seasons. When they are ready to be eaten, pearl onions have a mild and sweet juicy flesh, and are also grown for their thick, long, tender white stems.
In cooking, chefs use the silverskin bulb onion in preparing mixed pickles with a mixture of cloves, white vinegar and tarragon, and as a braised vegetable served with fried or braised meat. Both silverskin and pearl onions are used as a garnish because of their small size. The pearl onion is sweeter than the bulb onion and complements casserole dishes, succotash and Indian cuisine with its sweetness.
Silverskin onions are higher in calories than pearl onions because of their tendency to be pickled. Pearl onions can be part of a low-fat side dish, as a delicious way to enjoy a meal. One ounce of pearl onions contains 10 calories. The same serving of pickled silverskin onions is 21 calories. Both families contain equal amounts of sodium, carbohydrates and sugar.