The Wollersheim Winery, nestled on the bank of the Wisconsin River in Sauk City, near Prairie du Sac, is a national historic site that produces 1 million bottles of wine every year. The winery started cultivating in the 1840s, but by 1900, the vineyard was converted to accommodate more traditional Wisconsin crops.

In 1972, Robert and Joanne Wollersheim purchased the abandoned property and restored it as a family winery. In 1984, Philippe Coquard -- a winemaker from the Beaujolais region in France -- visited the Wollersheim winery where he met and fell in love with the Wollersheim's daughter, Julie. Today, Julie and Philippe operate the business.

In 1990, the family bought the Cedar Creek Winery in Cedarburg and consider it Wollersheim's sister winery. Together, Wollersheim and Cedar Creek produce 240,000 gallons of wine annually.

Most of the wines are marketed in Wisconsin, with the majority sold at the Sauk City and Cedarburg wineries. In Milwaukee, Wollersheim wines are available at most liquor stores and specialty grocery stores like Outpost Natural Foods and Whole Foods.

Prairie Fumé is Wollersheim's top-seller. The white, aromatic wine features a flavor that's both slightly sweet and slighty tart. Like most bottles of Wollerhseim wine, it costs between $11 and $13 per bottle.

In general, vineyards thrive on slopes because of increased water drainage, air flow and sun exposure. The Wollersheim winery is on a slope -- and near the river -- making the location ideal for growing the grapes needed to produce estate wines like the Domaine Reserve, Domaine du Sac, Ruby Nouveau, Prairie Sunburst Red, Eagle White and Prairie Blush.

However, the other Wollersheim wines -- including the popular Prairie Fumé -- are fermented on site but made with grapes imported from New York and Washington state.

"Wisconsin winters limit the types of grapes that can grow here," says Julie. "We make several wines from traditional grape varieties that simply cannot survive winter temperatures."

The Wollersheim estate features 25 acres of planted vineyards, and most of the acreage is devoted to French-American hybrids because of its ability to survive cold temperatures. Wollersheim's main grape is called Marechal Foch, which is a very reliable and versatile variety.

The Wollersheim Winery has 20 full-time employees and about two dozen part-time and / or seasonal staff members. Despite the struggling economy, the winery continues to prosper. Recently, the Coquards expanded the vineyards and the outdoor garden area when guests can relax and enjoy a glass of wine.

"We continue to grow because of the emphasis we put on quality and affordability," says Julie.

The Wollersheim Winery has received hundreds of awards over the years. Most recently, Prairie Fumé was honored with a gold rating at the 2009 Florida State Fair International Wine Competition and the San Diego International Wine Competition. Prairie Blush received a platinum rating at the 2008 New World Wine Competition in Ontario, Canada.

Tours are offered every day of the year, except on major holidays, at 10:15, 11:15, 12:15, 1:15, 2:15, 3:15 and 4:15. The tours are limited to 25 people, last about an hour and cost $3.50 per person, which includes a wine tasting.

According to Julie, the best time of year to tour the winery is during the late spring, summer or very early fall.

"The grapevines 'wake up' in April and grow all summer, with the grapes appearing in July," says Julie. "They are ripe and ready to pick around Labor Day weekend, but the vineyards are really nice to see anytime from spring until fall."