As you pass the Rock Point exit (No. 43) on Interstate 5, it's hard to miss the large vineyard off to the north.

As you pass the Rock Point exit (No. 43) on Interstate 5, it's hard to miss the large vineyard off to the north.

The neatly manicured rows of grapevines seem to go on forever. That's not surprising, since the vineyard covers 205 acres with 225,000 plants.

It's Del Rio Vineyards and Winery, and it plays a major role in the Oregon wine industry.

The winery makes about 10 wines under the Del Rio label, about 10,000 cases a year. But in so doing, it uses only 35 percent of the grapes it grows, says Rob Wallace, co-owner and on-site manager. The other 65 percent is sold to other wineries, about 25 of them. Clients include Ken Wright, Penner Ash Cellars, Edgefield, A to Z, Elk Cove, Solena and Sylvan Ridge.

The vineyard site, just west of Gold Hill, was originally a pear orchard dating back to the early 1900s. The pear trees came out in 1997, replaced by grapevines in 1998-99. The winery was built in 2004, expanded in 2007.

Del Rio grows 15 varieties of grapes: whites like chardonnay, pinot gris and viognier, reds like pinot noir, merlot and cabernet sauvignon, as well as malbec, grenache and sangiovese.

Current Del Rio label releases are 2007 Pinot Gris, Chardonnay and Pinot Noir, 2006 Malbec, 2005 Cabernet Sauvignon, Merlot, Syrah and Claret and 2008 Rose Jolee, a dessert wine. Its 2007 Viognier is sold out.

My favorites are the chardonnay, syrah and malbec. The chardonnay won a double gold award at the 2009 San Francisco Chronicle Wine Competition. The syrah, pinot gris, pinot noir and viognier also won medals there.

Del Rio's tasting room is open daily from 11 a.m. to 5 p.m. (6 p.m. in summer). The first taste is complimentary. Then it's $5 for an additional six tastes. A couple can split the $5 charge and get four tastes each (one comp apiece plus three paid tastes).

There's no charge if you are a member of the Rio Club. Members also get a 20-percent discount on purchases, along with other benefits. There's no cost to join, but members agree to accept periodic shipments of two bottles of wine.

Del Rio is at 52 N. River Road, Gold Hill. A multi-acre site in the middle of the vineyard is used for special events like the World of Wine Festival in August.

A SERIES OF WINE-RELATED workshops is planned from 1 to 5 p.m. Sunday, May 31, at ScienceWorks Hands-On Museum, 1500 E. Main St., Ashland. On the program are eight classes on the science behind wine and winemaking. Each will run 55 minutes, with two at a time running simultaneously.

Here's a schedule with time, topic and speaker:

1 p.m. — "Unraveling the Mystique of Terroir," professor Greg Jones, Southern Oregon University, department of environmental studies; and "Do the (Wine) Math," Anne Root, owner of EdenVale Winery and Linda Donovan, owner and winemaker of Donovan Wine. 2 p.m. — "Siting, Designing and Planting a Vineyard," Porter Lombard, Oregon State University professor of viticulture emeritus, and Randy Gold, owner of Pacific Crest Vineyard Services; and "Wine Chemistry 101," professor Steve Petrovic, Southern Oregon University department of chemistry. 3 p.m. — "The Real Dirt on Soil," Chris Hubert, vineyard manager of Quail Run Vineyards; and "Sensory Analysis: Taste With Your Nose," Condé Cox, wine writer and educator. 4 p.m. — "Vine Structure and Function," Chris Lake, director of Southern Oregon Wine Institute at Umpqua Community College; and "Crafting a Wine-Fine Meal," Kara Olmo, partner and winemaker of Wooldridge Creek Winery.

Cost is $49. Register at www.ScienceOfWineAshland.com or call 482-6767.

GRAPE EXPECTATIONS, the annual Soroptimist wine and food event, is set for 5:30 to 7:30 p.m. Thursday, May 14, at Pacific Wine Club, 3588 Heathrow Way, Medford. Tickets are $25 in advance, $30 at the door, available at Pacific Wine and Adam's Deli. Proceeds benefit local community-service projects.

VALLEY VIEW WINERY has been around for more than 30 years and has won more medals in competitions than any other Oregon winery. It's already won 17 this year, including one "best of show" and six golds.

The best-of-show winner was Anna Maria 2006 Cabernet Franc. Other honored wines — also all from the Anna Maria label — include 2007 Viognier, 2005 and 2006 Tempranillo, 2007 Chardonnay and 2007 Late Harvest Pinot Gris. A more complete list of winners ran on the Mail Tribune business page on April 8.

Cleve Twitchell is a retired Mail Tribune editor and columnist. E-mail him at clevelinda@msn.com.