NO one disputes the quality of German wines. The problem seems to be finding an occasion to drink them. O.K., we've solved it. Think of them as wines to listen to Wagner by.

Public television is midway through its four-night broadcast of Richard Wagner's monumental ''Ring des Nibelungen.'' The four operas of the ''Ring'' cycle are full of long, seemingly endless, expository passages that do absolutely nothing to move the story along. Better to think of them as Wagnerian time-outs, the 19th-century equivalent of beer commercials, much more profitably spent in a trip to the refrigerator or - you must have seen this coming - the wine cellar.

For reasons that are mostly obscure, Germany has shared only marginally in America's love affair with the grape. It probably has something to do with our perception of good wine as dry and the tendency of good German wines to be sweet.

In fact, most Americans prefer their wine at least slightly sweet. Lambrusco, white zinfandel and wine coolers are all sweet. Even some of our best-selling table wines, which we think of as dry, often contain residual sugar, purposely left over from fermentation.

German wines, the best of which are white, are thought of as sweet, but it's more complicated than that. In the best German wines, sugar balances the exceptionally high acid common to wines made in such far northern latitudes. In wines without abundant acid, the sweetness becomes cloying and flabby. (Many cheap German wines are made this way.) To confuse things a bit more, there are a number of dry German wines on the market now. They are good enough, but they are unfamiliar quantities in an already overcrowded market. Besides, for listening to the ''Ring'' we want to stick to tradition.

The Rhine River is central to the ''Ring.'' The first opera is ''Das Rheingold,'' the Rhine gold; to make the point, it opens with the Rhine maidens cavorting in the river.

And where do the greatest German wines come from? From the banks of the Rhine. The vineyards stretch from the Swiss border to Bonn, but the best are to be found in a small area from Walluf, west of Wiesbaden, to Assmannshausen, just 20 miles to the west. This is the legendary Rheingau, home of the Lorelei and lair of the Rhine maidens.

Tonight's opera, ''Siegfried,'' doesn't actually take place in the Rhine, but the central theme of the ring remains. That's as far as I will go regarding the plot. Try to fathom it and you will need something stronger than a delicate Rhine wine. And at 4 hours and 20 minutes, there will be plenty of time for refreshments.

German wines are admirably suited for television watching. They are, Hugh Johnson writes in ''The World Atlas of Wine'' (Simon & Schuster), ''so full of character and charm, and if the word does not sound too pedantic, interest, that they are best enjoyed, unlike French wines, alone rather than with food.''

Mr. Johnson goes on, ''A bottle of a spatlese or auslese from the Mosel or Rheingau is a complete experience from which food, however good it may be, can only detract.''

To explain: the best German wines are rated by grape sugar content, starting with kabinett and rising in intensity through spatlese (meaning picked late, when the grapes are riper and therefore sweeter) and auslese (for the choicest late-gathered grapes) to beerenauslese (choicer still) and trockenbeerenauslese, the sweetest, rarest and, naturally, most expensive. Spatlese and auslese wines are the best for aperitifs, although some enthusiasts enjoy them with certain rich dishes, just as Sauternes fans like that sweet wine with foie gras and certain cheeses.

The 1988 vintage was a fine one in the Rheingau, following fine vintages in 1985, 1983 and 1976. The mind-bending names are an attempt to give every bit of data possible in the smallest amount of space.

The result is a type of information overload that has put people off German wines for a long time. Suffice it to say that the name at the top of the label is the name of the winemaker. The name of the wine itself usually begins with the village, followed by the vineyard. The next line specifies whether the wine is a spatlese, auslese or something else.

For example, one New York shop is offering the very fine 1988 Erbacher Marcobrunn Kabinett, from the Schloss Schonborn, at $13.50. Schloss Schonborn is the winemaker, Erbach is the town, Marcobrunn is the vineyard and kabinett is the quality level of the wine.

The same merchant offers the 1988 Erbacher Siegelsberg Spatlese, from Molitor, at $9.50. Erbach, again, is the town, Siegelsberg is the vineyard, spatlese is the quality level and Molitor is the producer. Why is this spatlese, a higher quality level than kabinett, less expensive than the first wine? Because the Marcobrunn vineyard is one of the most famous in Germany.

The Schloss Schonborn also owns part of the Hasensprung vineyard in Winkel, and the 1988 Winkeler Hasensprung Kabinett, around $11, is another good buy. From Langwerth von Simmern, the Eltviller Sonnenberg Kabinett (about $9) and Spatlese (about $13) are going to be excellent wines with a little aging.

The Rheingau may be the most famous wine area in Germany, but great wines are made in many others. And as anyone who has been to Bayreuth to see the ''Ring'' will tell you, the local restaurants are quite eclectic in the wines they serve. Fans of Mosel wines don't for a minute accept the primacy of the Rheingau and will put their Bernkastelers against the Rhine wines any day.

The fact is that many, many fine wines are made in Germany, and we are mostly ignoring them. They may not be perfect companions for our meals, but they are far superior to most of the less-than-dry wines we favor.

And as for California and German rieslings, the only thing they have in common is the grape. Most California rieslings are banal and one-dimensional. Anyone who enjoys riesling, and becomes familiar with the better German versions, will never look back at California.


Dolcetto d'Alba 1988, Pio Cesare, Piedmont; about $14. The dolcetto grape has been described, mostly by people with limited descriptive powers, as the Italian gamay. Gamay, you will recall, is the grape of Beaujolais. Both grapes produce relatively fruity red wines that can be drunk young, but the resemblance ends there. Dolcetto is more tannic, more robust. It's a bit harsher in taste and typically Piedmontese in style, meaning that while much lighter in body, it still resembles the bigger wines of the region, like Barolo and Barbaresco. In fact, it comes off as much more mature than it really is. There are six or seven communes in Italy that are entitled to combine their name with that of the grape to form the official appellation. Alba is the best-known and Pio Cesare is a well-respected name in the region. The name dolcetto is misleading because it implies sweetness, but the wine is dry. It is a delightful table wine in the warm months.

Photo: Siegfried Jerusalem and Hildegard Behrens in a scene from ''Gotterdammerung'' in ''Ring des Nibelungen.'' (Beatriz Schiller)