It's a capital idea: finding who has D.C.'s best ice cream

Just a minute while I blot the mint Oreo-cookie ice cream off my notes, then I'll tell you about the real power struggle in Washington this summer. It's taking place, not behind the locked mahogany doors of Capitol Hill committees, but in the sizzling streets of the outer city. Where ice cream lovers duke it out as the battle lines form outside the ice cream boutiques all over town.

Perhaps the fiercest battles rage in trendy Georgetown, where there are half a dozen shops for homemade ice cream within a few scoops of one another along the main drag (known as Wisconsin Avenue). On this ice cream strip the sidewalks are adrip with signs of the fracas.

Slugging it out side by side, for instance, are Steve's Ice Cream, fresh from Boston, and Swenson's Ice Cream Factory, a branch of the California chain. Steve's had drawn a crowd of the curious this summer for what can only be described as couture ice cream. You order the flavor you want, then choose any one of a series of ''mix-ins'' that create a custom-tailored ice cream.

A businessman in a tan suit, for instance, hurries in for Steve's coffee ice cream with Reese's Pieces as a mix-in. Sam Brumbaugh, a counterman in an orange ''Prep Eats'' T-shirt gives it his ''karate treatment.'' He slaps a hunk of ice cream down on a marble slab, grabs a scoop and a silver ''spade,'' and begins pummeling the hard ice cream as a chef would a veal cutlet. When the ice cream is semi-limp, he grabs a handful of peanut-butter-flavored Reese's Pieces candies and smashes them into the ice cream. He beats them with the scoop and spade until they're pulverized into the cream, then blends it briefly. Swooping it into a cup, he hands it to the customer, who beams like a small boy.

Customers at Steve's tend to have the slightly glazed expressions of children in a penny-candy store trying to make decisions. It's not just all the wildly flavored ice creams - from cinnamon nutmeg to oatmeal-raisin cookie, or malted chocolate to banana-cream pie. It's also the confusing variety of mix-ins that can be added to them: crushed Heath bars, granola, butterscotch chips, M&Ms, walnuts, almonds, coconut, Oreo cookies.

''Honey-walnut ice cream with mixed nuts,'' finally sighs a girl in blue jeans and white T-shirt after minutes of agonizing. Another girl, in green T-shirt and braids, succumbs to Oreo ice cream with chocolate-chip mix-ins. At Steve's, as at every ice creamery we visited, Oreo-cookie ice cream is the biggest seller this summer.

Steve's, which offers about 48 flavors, sells ice cream that is around 14 percent butterfat and contains 35 percent air. Economy ice creams have high amounts of air - up to 50 percent - and lower percentages of butterfat (10 to 12 percent). The higher the butterfat content, the richer the taste.

Next door, at Swenson's, one of the earliest ice cream hangouts in the area, there are dozens of dazzling flavors from which to choose. They include Swenson's variation on Oreo ice cream, called cookies 'n' cream.

The store has an old-fashioned ambiance, with Tiffany lamps, tan and brown daguerrotype wallpaper, marble counters, and rust-colored leatherette booths.

Swenson's smells like the ice cream parlors of the past, a mix of sweet cream and cold marble. The butterfat content of its ice cream, is 14.1 percent, says shop owner Jesse Hamad, whose favorite flavor may be caramel cashew. It's hard to decide, when there are 55 to choose from, including bubble gum, cherry cheesecake, peanut butter cup, sticky chewy chocolate, caramel turtle fudge (the candied kind, not the tortoise), and confetti (strewn with M&Ms.)

Mr. Hamad says competition hasn't been a problem so far this summer. But the cool weather may melt off some of the profits for shops that rely on ice cream alone. (Swenson's has a back-up line of sandwiches and other nibbles.)

Further down the ice cream trail is Cone E. Island, a shop specializing in homemade (twice daily) sugar cones that actually come still warm from the griddle. Flavors like cinnamon and maple can be specially ordered. The griddle is an ornate wrought-iron number, looking a little like a cross between a chandelier and a hot plate, into which a batter is poured and cooked to crispiness. The ice cream flavors vary daily, and the list is relatively small, including choices like mocha, chocolate-mint chip, black raspberry, and tin roof (vanilla ice cream and chocolate-covered peanuts).

Shift manager Joanne Baye notes that while the best seller is - yes - Oreo-cookie ice cream, the real piece de resistance and ''the one we can't keep enough in stock'' is Old South Fudge Pie. It consists of chocolate ice cream, chocolate chips, Oreo cookies, graham crackers, chocolate fudge, and caramel all smooshed up together - in a sugar cone.

This smooshing up of sweet ingredients into already-sweet ice cream is one of the phenomena of the current season. Candied ice cream is all over the place this summer. It's as though urban grownups have suddenly been smitten with the craving for supersweets that generally affects only seven-year-old summer campers away from home for the first time. Even E.T. and friends might hesitate over stone-ground Reese's Pieces mixed into ice cream already flavored with Oreo cookies. But plenty of grownups are bellying up to ice cream bars to order such candied snacks.

At a downtown shop called Inside Scoop, for instance, one of the popular flavors is called ''competition'': vanilla ice cream containing mixed-in M&Ms competing with mixed-in Reese's Pieces. Another favorite is M3 ( called ''M to the third power,'' or ''M cubed,'' because it contains mocha ice cream plus M&Ms.) In case flavors like honey grapenut, mango, and chocoholic aren't rich enough, Inside Scoop also offers the usual line of toppings plus snowcaps: yogurt raisins, nonpareils, licorice, and Good-N-Plenties.

In the dark, ice-cream-ridden depths of Inside Scoop, we ran into a friend who had abandoned his attache case momentarily to sneak a dip of chocoholic ice cream. He said it was unbeatable. One of the shop owners, Andrew Shapiro, says chocoholic's dense taste comes from combining several varieties of chocolate.

Mr. Shapiro says his ice cream has 17 percent butterfat, with extra flavorings, and is 33 percent air: ''You have to put more flavor in a 17 percent butterfat than in a 14 percent, to punch the taste through the cream. When you have a good-textured ice cream with enough cream in it, it tends to be bland otherwise.''

Lawyers sometimes abandon their depositions for double scoops in Washington; both Andrew Shapiro and his partner, Jerrold Klein, are lawyers. So is Bob Weiss of another ice cream haven, Bob's Famous. Mr. Weiss, an emigre from Boston, found he couldn't get the kind of creamy homemade ice cream he was used to in Boston, so he started his own shop.

There was already a Bob's selling soft ice cream in the phone book, so he decided to call his place Bob's Famous to single it out.

His philosophy is: ''Making ice cream is more fun than law. In law, you're always fighting.''His shop carries as many as 200 flavors, ''including quite a lot of weird ones'' that customers request.

The menu changes daily, so if you find maple spice one day, it may be replaced by cinnamon the next. Among the offbeat flavors Bob's Famous offers are Butterfinger (from the candy bar), orange-chocolate-chocolate-chip, chocolate moose, honey graham, pina colada, Mozambique fudge, and an Australian black-currant sherbet that packs a punch like a kangaroo's tail.

Bob says he has a whole range of sherbets he's currently experimenting with: cantaloupe and mango, for instance. Customers can commission new flavors. One Washington opera singer commissioned a special Bob's Famous flavor, an amorous almond taste, for her wedding. Bob says his ice cream varies from 15 to 17 percent butterfat, depending on the flavor, with about a 30 percent air ratio.

''A pint of my ice cream weighs between 15 and 16 ounces, practically no air'' he says proudly.

Bob Weiss, who may be Washington's own emperor of ice cream, is doing so well that he plans to open two more stores soon. The original shop - it's on Wisconsin Avenue, too - has the folksy ambiance of an old cracker-barrel store. The walls are covered with murals featuring bright-blue skies and giant bananas, pineapples, apples, and strawberries. A bulletin board with community notices and press clips lines the opposite wall. There are stacks of local newspapers next to the tables..

My ice cream associates, Tracy Sullivan and Cece Barnett, who helped research this story, got in a few licks for their favorites, but also recommended several others. On the whole, we found that Oreo cookie varies in consistency, creaminess, and crunch. All the products sampled were tasty. But the best version of Oreo ice cream, we thought, was from Bob's Famous, where Bob has a secret for the ideal Oreo ambiance - that of a cookies-and-milk snack many people remember from childhood. He says he does not mix the cookies in at the beginning with other ingredients, because this creates a mushier taste, but adds them at the last minute for the slightly crunchy texture he prefers.

We also gave high marks to Bob's cinnamon, which is like a creamy version of Thanksgiving-pie spiciness; to Inside Scoop's refreshing mango and its triple-threat M3; to Swenson's pungent cherry cheesecake; to Cone E. Island's tin roof in one of its home-baked cones, and to Baskin-Robbins silky pralines 'n' cream (although its peanut butter fudge had a divided vote).

The Baskin-Robbins chain, with its nearly 250 flavors, is, of course, a story in itself. Our Baskin-Robbins expert, Tracy Sullivan, has sampled nearly all and is a devotee of their jamoca almond fudge - but also found jamoca mouse royale, junglefruit sherbet, and golden-delicious apple sherbet real contenders. For back-to-school, Baskin-Robbins in September will offer Preppymint, a peppermint done in basic preppy shades of pink and green, and ''Here come the Fudge.''

We are, of course, talking about pricey ice cream here; gone are the days of the 25-cent scoop. These homemade ice creams range from 75 cents to $1.10 a scoop, and the addition of mix-ins or toppings can bring the bill up to close to

Finally, even in an area like Georgetown's ice cream trail, where Haagen-Dazs and Barricini are also slinging it out with the others mentioned here, the ice cream wars are not over yet.

As one ice cream magnate pointed out, a large vacant store in the ice cream strip will shortly be taken over by Thomas Sweet, the tigers of Princeton, N.J., scoopdom.