THERE MUST be as many methods for beating the heat as there are for beating the horses. Fortunately, more of the heat-beaters are winners, a particular blessing for those of us consigned to this inferno known as summer in Washington.

On a sweltering day, the sure-fire choice for my money is a cool glass of wine; in particular, a well-chilled German riesling. There's just enough alcohol (9 percent) to combat the blahs, ample acid to provide a zesty tang, enough sweetness to enhance the taste without cloying and fruity flavors to offer thirst-quenching safisfaction. The wines even smell cool and flowery fresh.

The lower levels of the German wine hierachy, the kabinetts and, frequently, OBAs from the better vineyards and areas of the Mosel or Rhine are the best choices to accompany informal summer meals and snacks or to drink by themselves. The Mosels are lighter and tend to be drier while the Rhines lean toward softness and fullness. Despite the ravages of inflation, good ones can still be found for $4 to $6.

The problem with selection is all those jaw-breaking names. Short of a crash course in the language, your best solution is a wine consultant who can steer you through the labyrinth.

As a stop-gap, here are a few personal choices. From A&A, one of the stores that still has a broad selection of those fine back-to-back vintages, 1975 and 1976, I recently sampled and liked, in this order, 1976 Ockfener Beckstein Kabinett, Winzerverein Irsch ($5.49); 1976 Eltviller Langenstuck Kabinett, Scholoss Eltz ($5.49); 1975 Holchheimer Kirchenstuck Kabinett, Staatsweinguter ($4.89), and 1975 Eltviller Sonnenberg QBA, von Simmern ($4.49).The Ockfener's crispness makes it an appropriate aperitif; the Langenstuck is probably the best to drink with food.

Most of the well-known 1979s, a vintage of some promise, especially for kabinett-quality wine, won't be arriving until fall. However, a number of the lesser lights have already appeared. Of the half-dozen I tried none begins to measure up to the four from '75 and '76, with only one really acceptable: Berkasteler Kurfurstlay Spatlese, von Prittwitz (MacArthur, $4.99).

There are quite a few 1977s and 1978s around. Based on those I've tasted, the two years don't offer much.

If you're interested in a big splurge, take a considerable step up in quality (and price) to the 1976 Erdenter Treppchen Auslese, C. H. Berres (Sir, $11.16 [sale price], Harry's $12.99, Georgetown Wine & Cheese, $13.95). Rich, full and flavorful, it could turn a steamy August day of sipping into something worth remembering.

Nothing bogs down a picnic, a hammock-and-wine session, or any event where wine is served, like a corkscrew that doesn't work. Screws that crumble corks, screws that require the strength of a weightlifter, screws that collapse when the going gets tough are as common as they are aggravating.

But thanks to an inventor named Herbert Allen, one has appeared that has me popping my tops. Called the "Screwpull" it looks and works like the books say a corkscrew should. It's the easiest, most effective corkscrew I've ever used. Ordinarily, it sells for arund $12 but MacArthur Liquors has been offering it for $8.95.

Some share the view of a British friend who holds that the perfect antidote to wilting weather is "a shady knoll and a spot of jolly reading." With that in mind I've been rereading Cyril Ray's "In a Glass Lightly," a happy collection of reminiscences about wine and wine drinkers.

Equally charming and generally devoid of any cool-shattering choler is "The Fireside Book of Wine," Alexis. Bespaloff's anthology of quotations, snippets, poems, short stories, essays and prints, some serious, some humorous, but all bound together by their author's common devotion to civilized drinking. Among the many authors represented are Dickens, Thackeray, Colette, Hemingway and Thomas Jefferson. Barnes & Noble (126 Fifth Ave., New York, N.Y. 10011) list it in their latest catalogue at less than half price, $5.98.

If you number yourself among those who look for a change to offset the "dog days" of summer, let me offer a wine suggestion. Instead of chilling a beaujolais or zinfandel to go with the cold cuts, pate and cheese, make it a nebbiolo d'Alba. Produced from Italy's premier grape, the nebbiolo, these wines are generally light, well-balanced and smooth, and they are ready to drink when bottled. And perhaps best of all, they usually sell for less than $4. In the past year I've enjoyed 1976 Granduca, 1970 GIRI AND 1974 victoris. i

Once you have a glass in hand you can follow the advice of the Greek poet who urged: "When Sirius (the dog star that appears during dog days) parches head and knees, and the body is dried up by reason of the heat, then sit in the shade and drink."