Summertime blues. Wild or cultivated, blueberries have flavor stay-power

`BLUEBERRIES as big as the end of your thumb, real sky-blue and heavy,'' just as Robert Frost described - are available nearly year around. But somehow the best time of all is summer.

Like peaches, raspberries, strawberries, and cherries, blueberries are truly summer fruits.

Even though you can find them frozen, canned, dehydrated, and preserved in all seasons, the best blueberries appear from the hot, sultry days of July to the frosty mornings of September.

In New England and Canada, the only places wild blueberries are commercially harvested, a mammoth crop of 80 million pounds is expected for the season now under way.

``About half of all the wild blueberries harvested, that is, about 35 to 40 million pounds, will come from the blueberry barrens of the state of Maine,'' says George Wood, executive director of the Wild Blueberry Association of North America.

Unfortunately for those who prefer wild blueberries and like them fresh, only about 3 percent of the North American wild blueberry crop goes to the fresh market. The majority of these tiny, wild blues go into processing.

``But there will be more wild berries for the fresh market soon - maybe double the amount in five or six years,'' Mr. Wood said. ``Consumers have been asking for them, but picking and sorting berries is labor intensive.''

Of the berries that are processed, 15 percent are canned and 82 percent frozen, Wood said. Processed berries go into commercial baked goods, ice cream, preserves, table syrup, and other products. Frozen berries are also widely used by institutions and restaurants.

It's the high-bush blueberries, juicy and luscious, that dominate the grocery stores. These cultivated berries are as different from their wild parents as today's sweet corn is from the corn grown by the Indians years ago, some people say.

High-bush blues are softer than the wild berries and are huge, almost as big as grapes. Five or six will make a spoonful.

The tiny wild berries, however, have an intense flavor. One cup contains about 400 wild berries, compared with 100 cultivated ones.

Wild ones are prized by bakers for flavor and because they keep their shape during baking. They have a short season - six to eight weeks. WHEN purchasing or picking fresh blueberries, you should look for dark blue color with a silvery bloom, which is a natural protective waxy coating. Choose those that are firm, plump, and dry. Store them uncovered and unwashed in the refrigerator.

When it comes time to bake your blueberry pie, which is the first thing your family will want in blueberry season, you'll find you can use fresh or frozen berries.

Karen Matheny of Framingham, Mass., has been making pies for her family for about 30 years. Now with a full-time job as a school principal, Mrs. Matheny says there's not much time for baking, but she still thinks it's well worth it to make piecrust from scratch.

``I use a wire pastry blender to mix the flour and shortening, and it makes a world of difference. Some people use two forks, but the blender helps make a fine, light crust,'' she says.

Today, most scratch pie bakers are over age 45, surveys say, but no matter what your age, don't be intimidated - even if you must save time with a pre-rolled and shaped refrigerated crust. The result will be a delicious dessert. The addition of vanilla ice cream makes blueberry pie the all-American summertime favorite.

Karen's Blueberry Pie 2/3 cup plus 2 tablespoons shortening 2 cups flour 1/4 cup cold water 3 cups blueberries 1 cup sugar 1 tablespoon lemon juice 1 tablespoon butter, optional Nutmeg or cinnamon to taste, optional

Preheat oven to 425 degrees F. In large bowl, combine berries, sugar, and lemon juice, and stir. Let stand a few minutes. If you're using frozen berries, let them defrost now.

Make plain pastry by mixing flour and shortening with pastry blender until size of small peas. Mix in water with a fork.

Divide dough into 2 parts and roll out thin on floured board. Line a pan with half the pastry; turn filling into pastry shell. Dot with butter or sprinkle with nutmeg and a tablespoon of flour, if desired. Place top crust over berries, cutting decorative slits in top to allow steam to escape.

Bake 10 minutes in hot oven. Reduce heat to 325 degrees F., and cook about 30 minutes more.

The following recipe for blueberry muffins won first prize in this year's Maine Wild Blueberry Muffin Contest for the McGilvery House Bed and Breakfast, Searsport, Maine.

Big Blues Muffins 1/2 cup unsalted butter 1 1/4 cup sugar 2 eggs 1/2 cup milk 2 cups flour 2 teaspoons baking powder 1/2 teaspoon salt 2 cups wild blueberries

Cream together butter and sugar. Add eggs one at a time, then add milk. Add flour, baking powder, and salt, and stir gently until just moistened. Fold in blueberries. Fill muffin tins quite full, and bake 25 to 30 minutes in a preheated 350 degree F. oven.

Wild Blueberry Jam 4 1/2 cups fresh wild blueberries Juice of 1 lemon Grated rind 1/2 lemon 7 cups sugar 1 cup liquid, natural pectin

Wash and crush berries, mix in juice, rind, and sugar. Boil 3 minutes, remove from heat, and stir in liquid pectin. Skim and pour into 6 sterilized glasses. Seal with paraffin when cold.

Phyllis Hanes is the Monitor's food editor.

Did you know that...

When chilled, fresh blueberries will last at peak flavor about two weeks.

Wild blueberries are especially good for baking. They maintain their shape and do not bleed.

If canned blueberries are used for breads, drain, rinse with cold water, and drain. This causes less ``streaking'' of the color.

Blueberries shouldn't be washed right before freezing. Frozen, they can be stored up to two years without losing their flavor.

In baking, frozen blueberries do not have to be defrosted.