Do you have a client looking for that unique estate property?  A four-bedroom estate situated on 20 acres in the heart of Napa Valley is back on the market for a chilled $42 million.

Like a fine wine, the property has aged and apparently increased in value since it was listed at $38 million a year ago. Since that time, 14 acres of grapes have sprouted, leading the owners to increase the value of the property.  Ginger Martin of Sotheby’s International Realty, recently told Forbes up to $2 million of the price hike is due to a recently obtained license necessary to build a wine business on site.

Named Whitehall Estate after its location at South Whitehall Lane in Saint Helena, Calif., the property is licensed for a 10,000-gallon-per-year production facility. Gregg Lynn of Sotheby’s International Realty, who co-listed the property with Martin, said the vineyard is ready to go.

“The vineyard, in its third leaf, will soon enjoy its first harvest enabling the new owner to consider creating a private label Cabernet Sauvignon wine.”

Designed by Bay Area architect Lewis Butler, the four bedrooms include two master suites. The 6,700 square-foot home also features four full baths and three half baths. Being situated in Napa Valley, it is only natural that it would include a steel-suspended system for displaying a wine collection. It has an indoor kitchen and an outdoor kitchen, along with a three bedroom guest house, complete with its own pool.

Martin has sold several properties in the area over the years, including a home in Sonoma for $35 million in 2010, which remains the highest price achieved for non-winery in the area. The Sloan Estate, a commercial vineyard with a chateau-style home on the grounds, sold to an investor group in 2011 for $40 million.

“Napa Valley hasn’t hit the Miami, Hamptons or Malibu highs, but that is not to say there aren’t $40 million properties. They simply are not for sale.”

According to the listing, the living and dining quarters open to an outdoor pool pavilion featuring a lava-stone fireplace and an infinity-edge swimming pool and spa. A landscaped courtyard at the entrance to the home is set off by an inlaid water feature by sculptor Archie Held. There also is a sports court and a putting green that can double as a helipad.

Martin pointed out that the owner developed and built the property and then realized he wouldn’t be able to spend as much time in the area as he’d hoped and decided to market the property. She said the property has plenty of appeal.

“There couldn’t be a more gorgeous, glamorous site.”