For fresh use, be sure to select daikon that is firm and crisp. Limp roots with withered skins are past their prime and are likely to be dry inside. When using it as a cooked vegetable, keep in mind that daikon has dense flesh and must be cooked well. Daikon's flavor is sweetest when it is completely tender. You can test whether it is done by inserting a toothpick or skewer into the thickest part of the vegetable. It should pierce the flesh easily, with little resistance.
Daikon is also available dried. Some dried daikon (also called kiriboshi daikon) is still being made by a traditional process carried out only in the winter months. Fresh daikon root is simply shredded, then allowed to dry thoroughly in the sun. Drying gives daikon a sweet, mellow taste and preserves most of its nutritional value. Stored in a sealed package in a cool, dry place, dried daikon keeps well, thus providing a good supplement to a winter diet.
To reconstitute dried daikon, soak it in lukewarm water for 10-15 minutes if you are planning to boil it, 30-60 minutes if sautéing or pickling. Remove daikon, squeeze out excess water, chop, and add to soups and stews or sauté alone or with other vegetables.