A primer on grapes
Grapes come in green (also called white), red and blue-black, and in thousands of varieties, Everyday Food magazine points out. Here are a few that are used commercially:
For eating fresh, green seedless Thompson and Red Flame (both firm and mild) are among the most common.
Muscat (sweet and fragrant, greenish gold) are often used for making wine and raisins.
Zante (blue-black, tiny and seedless) are used for making dried currants.
Sweet-tart, blue-black Concord grapes are used mostly to make juice, jams and jellies.
How to buy them: Grapes should be plump, with smooth, unbroken skins, and be firmly attached to the stems. The green ones are at their sweetest when they have a pale-yellow hue. Often grapes are covered with a whitish "bloom," which is a natural protection against loss of moisture and spoilage.
How to store them: Discard damaged grapes, place bunch in a plastic bag, and refrigerate up to three days. To avoid destroying the bloom, rinse just before using.