IT'S A HYPE, it's a fad, it's a fashion, but every year I fall for it, hook, line and sinker.

Or, should I say, cork, glass and sediment, because, as every wine buff knows, le Beaujolais Nouveau est arrive.

And even though I really do know better, I could not help but join crowds of others who also should know better in performing the annual rite in Harvard Square.

"The publicity and the fad have to be a part of it," said Aaron Fox of Eliot Street's "A Wine For All Reasons," in which five cases of the stuff were snapped up in two hours. "But it is interesting in itself," Fox added.

Its promotion hasn't been exactly tame: horses, helicopters, even parachutists descending from the skies onto the banks of the Thames with bottles of Beaujolais lashed to their plummeting bodies. A well-greased media lap it up every time. Why?

It's a craze that began in France, where trendy Parisians got wise to the fact that wine could still be fun if you drank it fresh and young, instead of first hiding it away in the cellar for 50 years.

It was so much fun, they decided, that very soon they were drinking it in bacchanalian quantities. Brand new Beaujolais was the young wine of choice. made and then bottled at extraordinary speed from grapes harvested only a few weeks earlier. No fashionable cafe was complete without it: the more

Then the Brits caught on. As midnight struck on the night when the latest year's wine was officially released, dashing restaurateurs would load up their sports cars and speed back through the darkened French countryside in order to be the first to serve the Nouveau at their cosmopolitan London bistros.

The race was born, and the good Beaujolais burghers rubbed their hands with Gallic glee as they exploited a miraculous new way of turning a feeble wine into a majestic profit.

Each November now, a common release date is declared, and incredible quantities of thin red wine are hurtled through Europe in prime time for consumption and consideration next morning.

The Atlantic Ocean, of course, is a rather different proposition from the English Channel, but it takes more than a few thousand fathoms of briney to keep a fad from Harvard Square.

This year's Beaujolais Nouveau was released in France on November 21, and by the following day it could be found in the Square.

Fox said his wine, selling at $5.99 a bottle, had been brought in by air and was attracting both regulars and trend-watchers alike.

Other wine sellers, like the Harvard Wine Company, were trying to keep the price down to the $5 mark by bringing in their Nouveau by sea. Supplies are expected immenently. "It does very well," said their man Jim Black. "As much as we get it's gone."

The University Wine Shop, too, were eagerly awaiting supplies, even though wine manager Betsy Shea was somewhat less than intoxicated by the prospect of the actual quality of the wine.

"It is mostly a fad," she admitted. "The press make such a big deal out of it."

Press notwithstanding, customers have been asking for the overripe grape juice since September. After all, this is Cambridge.

But of course, an investigative journalist must find it only proper to sample a bottle himself. Besides, I couldn't resist it.

Well, surprise. This year's Beajolais Nouveau is just as bad as last year's, and, as far as I can remember, just as bad as the year's before. Once again, I have fallen, headlong, for something which I know is a totally gargantuan hype. And so has everyone else. The trouble is, I know that in November 1986 I--and crowds of others around me--will fall victim to the same hype.

After all, this is Cambridge.