Old Westminster Winery’s new property lies on sloping land near Clarksburg, Md. The crumbling slate rock in the soil should prove hospitable to grapevines. (Ashli Johnson)

The alert popped up on Drew Baker’s phone one Sunday morning in July. A 117-acre parcel of farmland near Clarksburg in northern Montgomery County, Md., had come on the market. And he recognized the address.

“We had already looked in that area, so we knew it was promising,” says Baker, vineyard manager for Old Westminster Winery in Westminster, Md. “My wife and I went there, saw the site and immediately dropped a pin,” he says, referring again to his phone. Standing at the top of a ridge, looking west toward Sugarloaf Mountain and the Blue Ridge, he sent the GPS coordinates of the site to Ernest “Bubba” Beasley, a geologist in Charlottesville who was helping Baker scout for new vineyard land.

Within hours, Beasley emailed information about the land, based on topographic maps and historical records. Within days, Baker and Beasley were analyzing soil samples. And just before Christmas, Old Westminster Winery became the owner of Burnt Hill Farm.

“We found it!” Baker exclaimed on the winery’s blog. And with that announcement, Maryland’s most dynamic winery was expanding.

Old Westminster is a family project, led by three photogenic and charismatic siblings. Drew Baker, 29, tends the vineyards on the family farm near Westminster; Lisa Hinton, 27, makes the wines; and Ashli Johnson, 26, handles the front of the house and special events. Their parents, Jay and Virginia Baker, entrusted the trio with the family farm in 2008. After three years of study and apprenticeship at wineries around the world, they planted their first vines in 2011.

Old Westminster created an early sensation at the Drink Local Wine conference in Baltimore in 2013, featuring wines made with purchased grapes. The Baker siblings quickly joined the ranks of wineries leading Maryland’s wine renaissance, along with Black Ankle, Boordy with its replanted vineyards, and Big Cork. Last year, the Bakers released Maryland’s first pétillant naturel sparkling wines, and the Daily Meal website named Old Westminster one of the country’s top 101 wineries to visit.

Variations in the terrain at Burnt Hill Farm should allow Old Westminster to plant several varieties of grapes and make more interesting wines, says Ernest “Bubba” Beasley, a geologist who consulted on the purchase. (Ashli Johnson)

Burnt Hill, nestled on the southern edge of Little Bennett Park, lies on a steep westerly slope on the southern edge of what Drew Baker calls “the mid-Maryland ridge,” an elevated stretch of land that roughly follows Route 27 (called Ridge Road in some parts) from Clarksburg through Mount Airy to Westminster. The area includes the Black Ankle, Old Westminster and Elk Run wineries, and it’s where Hamilton Mowbray pioneered vinifera vineyards in the 1970s. It parallels South Mountain and the Catoctin Range about 30 miles to the west, where Boordy and Big Cork have produced the wines that won the last two Maryland Governor’s Cup trophies. The soil is phyllite, or decomposing slate, the rock easy to crumble by hand. The farm’s name comes from the late 1800s, when the owners despaired of growing crops in the nutrient-poor soils and made money by burning trees and brush to make charcoal, potash and lye.

Poor farming soils grow better wines, and Burnt Hill should be ideal, Beasley told me. “The high gravel content and the loose soils mean low water retention — important in our humid climate — while the vine roots will be able to dig deep. Variations in the slope — northwest or southwest — will allow them to plant several varieties, to make more interesting wines,” he said. “The soybeans in the field during our site visit last summer were struggling, a great sign for wine quality.”

Burnt Hill could help Old Westminster produce “iconic Maryland wines,” Baker told me. He said the siblings had come to the realization that “to make more nationally significant wines, we’d need to expand.”

The three, along with Beasley and consulting viticulturist Lucie Morton, will spend the next two years getting to know the site. Baker has already installed weather beacons throughout the property to measure temperature shifts, dew points and precipitation. In March, Beasley will do electromagnetic mapping to measure the soil’s electrical conductivity. That will tell them where to dig soil pits to observe the structure and variations in the soil.

During that time, “they’ll see where the snow melts first” — indicating a sunny spot — “and where the wind currents flow,” Morton says. That will help determine not only where to plant but also which varieties to plant and how to orient the rows.

Baker plans to plant 30,000 vines in spring 2019. That would cover about 17 acres of the site with densely planted vine rows, he said. They might be able to produce a small crop in 2020, but their first commercial-size crop will be in 2021. With vinification and barrel aging, we probably won’t be able to try these wines until 2022 or later. That’s one reason wines produced on such a small scale are often expensive.

“The site will reveal itself to us over time,” Baker says, with a winegrower’s patience. “If you hurry up and plant, you can make mistakes.”

And although he doesn’t yet know exactly which grape varieties he will plant, he says he’s sure of one thing: “This is a red-wine site.”

All the Maryland wineries mentioned, and more, will present at the fifth annual Winter Wine Showcase on Jan. 26 at the B&O Railroad Museum, 901 W. Pratt St. in Baltimore. The event includes a sparkling-wine reception from 6 to 7 p.m. and a grand tasting from 7 to 9:30 p.m. For ticket information, go to marylandwineevents.com.