Some apple varieties are easily placed in a specific category. Red Delicious apples, for example, have a sweet taste that makes them ideal for fresh eating. They become mushy and bland when baked. Other apple varieties are sweet enough for fresh eating, but have a crisp texture that holds up well to baking so they fit in several categories. A few apples are truly sour. They are most often used for baking, cider or sauces.
Crab apples are classified as any apple smaller than 2 inches in diameter. Most crab apples are classified as tart apples. Some varieties are too small or tart for human consumption, but many varieties are suitable for sauces and ciders. Try Everest, Maypole, Siberian, Whitney or Wickson varieties for sour apples. Centennial is sweet enough to eat fresh.
Granny Smith apples are probably the most well-known sour apples. These crisp, green apples are excellent in pies, apple sauces and baked goods. Many people enjoy them fresh, too, although they have a tart, acerbic flavor that doesn't appeal to everyone. Jonathan, Braeburn, McIntosh, Cortland and Winesap all have slightly sweet, slightly tart flavors with spicy undertones. Use them for baking, as well as for fresh eating.
If you're lucky to have an apple tree, try fruits at varying stages of ripeness. An apple is ripe when the ground color, or color underneath any red blush, changes from green to light green, yellow or cream, depending on the variety. These apples are at their most sweet and flavorful. However, if you like apples on the tart side, pick them a week or two early. They'll be juicy and crisp, but less sweet. Apples picked too early are starchy, bitter and dry.
Uses and Storage
When cooking with apples, select at least two or three varieties for a more complex, spicy flavor. Add citrus zest and juice to pie filling and applesauce for a bit of tartness. Sour apples are crisp and store well. Keep small amounts of apples in perforated plastic bags in the fruit crisper of the refrigerator. Store larger quantities in boxes lined with perforated plastic in an unheated garage where temperatures range between 35 degrees Fahrenheit and 40 degrees Fahrenheit.