THE ULTIMATE lemonade isn't pink, but it does sparkle. The best thing about it, however, is that it only takes seconds to make--not the long hours of sitting in the sun necessary for brewing solar iced tea. In France and Italy, where lemonade is raised to esthetic heights, this lemonade would be called citron presse--a drink made by pressing, hard, on a lemon.

To some, nothing is as thirst quenching as a tall glass of cold, but not icy, water. To others, the solution is a citron presse, followed by a cold glass of the same water used for the lemonade. Then, the most wicked of summer days feels more tolerable.

The ultimate lemonade is a pure drink, made in the simplest way possible, with the best ingredients--a good lemon and some great mineral water. If you choose to make the ice cubes for the drink out of mineral water--unsparkling, of course--all the better. To the recipe: LEMONADE (Makes 1 drink) 1 lemon 1 to 2 teaspoons superfine granulated sugar Ice cubes Mineral water

There are two kinds of lemons: thick-skinned ones with little pulp and juice, and smaller thin-skinned lemons with lots more juice. Buy the smaller ones if you can find them.

Place the lemon on a secure countertop. With the palm of your hand held stiff and flat, roll the lemon back and forth to soften the inside flesh. This way, the lemon yields more juice. If the lemon is very hard, the same thing can be accomplished by dropping the lemon onto the floor and rolling it back and forth with the sole of a shoe. If you use the latter technique, do rinse the lemon before squeezing.

Cut the lemon in half and squeeze the juice into a 12- to 14-ounce glass. Strain out the seeds, if desired. Stir in sugar to taste. (One teaspoon is barely sweetened, 2 teaspoons seem about right, and 3 teaspoons, or a tablespoon, is just a little on the sweet side.)

Add ice cubes almost to the top, then fill with water and give one very gentle stir.

The ultimate lemonade is made with a French mineral water called Badoit, about $2 a bottle (available at the Watergate Safeway and the International Safeway in McLean). Badoit has an elegantly crisp taste and a very fine sparkle--what wine people call a petit moussant, a tiny bubbling that perfectly counterbalances the acid flavor of the lemon juice. Second choice would be Fuigi, an Italian still water.

If Badoit (or Fuigi) isn't available or desired, use the still or sparkling water of your choice if you live in an area where the flavor of the tap water would utterly destroy the lemonade. Tap water that is good and hard is fine. VARIATIONS

Limeade--Use two limes instead of one lemon.

Pink lemonade--a heresy but nonetheless satisfying. Add a little grenadine and less sugar with the lemon juice.

Hot lemonade--Use the juice of two lemons, and add very hot or boiling water. Obviously, omit ice.