WINE GRAPES don't hang just anywhere. The grapes that make quality wine have definite geographic preferences. They like hillsides, for example, and they definitely prefer warm days, cool nights, lots of sunshine and especially, this time of year, relatively low humidity.

And of course, no decent wine grape will be caught raisining where there's much air or water pollution.

If you think the best places for wine grapes sound exactly like the best places for you, maybe you should consider an autumn weekend in Pennsylvania wine country.

Every year, more and more Pennsylvanians are visiting the state's roughly 70 wineries. More than 620,000 Pennsylvanians toured, then drank the state's lofty grapes this year, a number that's grown steadily by 5 percent in the last two years, according to the Pennsylvania Wine Association.

The Pennsylvania wine industry ranks fifth nationally in grape production and eighth in wine production with 14,000 acres of grapes, according to the Pennsylvania Wine Association. Pennsylvania wineries produced 600,000 gallons of wine in 2001 - a 300 percent increase from 1981.

With all this wine flowing freely, harvest time is prime time to visit - for those who would like to talk crops or just, um, hang with the grapes.

For Philadelphians, there are three main routes out of the city and into a vineyard for a day trip. Tastings are free and most wineries have some picnic facility so you can pack a lunch and enjoy a bottle of wine within a few yards of where it was made - or while it's being harvested and made. All the wineries are licensed to sell wine on premise and some offer special deals available only at the winery.

It's a good idea to call ahead and see if there's any weekend entertainment scheduled - some wineries offer concerts and other special events.

The Brandywine River Valley

Embedded someplace in the American consciousness is a vision of the small winemaker - living close to the land, rugged, independent, resourceful and yet literate, sophisticated and sensitive.

Like most good myths, it has a foundation in reality, and you can go see the real thing in a few places: Napa, Willamette and just south of Philadelphia in the Brandywine Valley.

The Chaddsford Winery is probably the most beautiful wine establishment in Pennsylvania. You turn off Route 1 into an enclave that's both carefully manicured and softly unpretentious.

The winery is tucked behind a visitor center, and there's a small demonstration vineyard on the front lawn. There are regular tours and free tastings, but if you know all you want to know about winemaking, you can simply bring your lunch, buy a bottle and find a place under a tree.

Before you leave, treat yourself to a bottle of the very European Philip Roth Chardonnay or the ultra-American Chambourcin.

When you're done, it's minutes to Longwood Gardens, the Wyeth family's Brandywine River Museum, Winterthur, the American Helicopter Museum, antique shops, the Brandywine Battlefield state park, and lots of horse-country restaurants and inns.

The Lehigh Valley

Drive a few miles north on the Blue Route and it's possible, if you squint a little, to imagine yourself in the agricultural, underpopulated America of 50 years ago.

The countryside is composed of rolling hills, cornfields and cows. The barns are red, and the picket fences are freshly white.

It's the kind of country where you'll run into the Lynnville Hotel, arguably one of the most beautiful and beautifully preserved barrooms in the country. It's been in business since 1878 and the sight of its stamped tin ceiling is enough to make the trip worthwhile for a bar-loving soul.

You'll also run into unrelenting friendliness - the people, like the grapes, seem to have grown in a particularly congenial mesoclimate.

Blue Mountain Vineyard has a huge, open tasting room that looks out over ponds and up a hill to the orderly fecundity of its vineyards. Winemaker Joe Greff, a pleasantly Bohemian ex-New Yorker, is likely to be pouring and talking about his wines. Tasting is done along a long bar that potentiates Joe's personality and gets people talking.

Be sure to taste their 2000 Pennsylvania Reisling, a recent Wine Find selection in this paper.

Clover Hill Vineyard's strong suit is a tasting room with lots of little bars and plenty of people to pour your wine into well-designed tasting glasses. Their picnic grove is beautifully laid out in the shade of a grove of trees. Position yourself to avoid the view of suburban sprawl across the road, and enjoy their 1998 Chambourcin.

Pinnacle Ridge Winery is so small that it only sells its wines at the vineyard. Good. The wines, especially the three sparkling wines, are remarkable, complex, well-made and, at $12 to $14, bargains. (Be sure to try the Veritas 2000, a Bordeaux blend and the Rhônish 2001 Chambourcin.)

The tiny tasting room is below a hayloft and adjacent to the winery, so you taste in an atmosphere of must and grass and sour wine from the drains. The effect is far more charming than the description and a great relief from the sterility of most wine-tasting environments.

Pinnacle Ridge lists its address as Kutztown, but it's really in Krumsville. That fact makes it possible for you to get your picnic lunch made up at the Krumsville Inn, which I hereby nominate for National Barroom Landmark status right beside the Lynnville Inn.

Manatawny Creek is a winery that only sells from the vineyard. The trip to Douglassville is more than justified by the chance to taste their 2001 Cabernet Franc, super-concentrated and delicious.

This is the closest of the Lehigh Valley wineries; you can stop here on your way to the thoroughly depressing Reading Outlet Center or turn north to the rest of the vineyards.

If you don't want to spend your entire day tasting wine, you can have a crunchy granola fit at the Rodale Publications Visitors' Center or visit Crystal Cave. For collectors, there's Renninger's Antiques Market: a collection of 250 dealers who converge in Kutztown every weekend.

Salut!