When San Francisco is not enveloped in fog, Sutro Tower can be seen from all over the city — and that's what makes it an ideal location for fog collection.

"On an average day last summer, we'd collect around 17 gallons," says Chris Fogliatti (ironically, the g is silent), a volunteer for FogQuest Sustainable Water Solutions, a Canadian not-for-profit company.

In an unusual, yet mutually beneficial partnership, FogQuest collects scientific data on fog patterns and collection efficiencies while Alameda's Hangar 1 Vodka collects the resulting water to make, well, vodka.

At the base of the nearly 977-foot television and radio antenna sits a pair of mesh screens stretched over a metal framework, and below that, a bucket. It's all very low-tech: Tiny fibers between the two layers of the mesh collect water as fog passes through, much like the diminutive leaves of a redwood tree pull moisture from the air. Gravity does the rest of the work.

"There's a lot of synergy with these broadcasting towers and fog collecting, they both have similar requirements," says Fogliatti, noting that being "on a coast hilltop, close to the marine layer, or the fog bank, and in a windy area," is ideal for both the antenna and the fog collection operation.

Hangar 1 supports FogQuest's research and development, as a portion of the proceeds from their limited production of Fog Point Vodka ($134, retail) is used to set up and maintain fog collection points. In 2016, all profits from the sale of the vodka, which amounted to nearly $250,000 during the 2016 run, were donated to local water conservation organizations and to fund more fog collectors.

For 2018, a portion of the profits will be donated, and production has increased to 5,000 bottles.

Six years ago, the United States Geological Survey created the Pacific Coast Fog Project which brings together researchers to collaborate and study fog's impact on our environment. Data from FogQuest supports such research, which Fogliatti says is important in fog's impact on ecology.

"The hours of fog has decreased by three hours per day over the past century" in coastal areas, says Fogliatti, citing a 2010 paper by two University of California researchers. "That has a pretty broad impact because that coastal ecosystem depends on that fog," he adds.

The distillery first launched Fog Point in 2016, when the company started experimenting with FogQuest to collect fog from the Presidio in San Francisco and Tilden Park in the East Bay.

Head distiller Caley Shoemaker says Mount Sutro produced a more prolific yield, so they continued there, but shifted the other collection points to Half Moon Bay.

"It actually turned out that Sutro Tower collected still more fog," Shoemaker said, reinforcing perhaps an obvious observation to anyone who has looked across at San Francisco on a foggy morning and seen only the radio antenna, and now Salesforce Tower, piercing the marine layer.

The San Francisco fog is just one part of the process, however. Also new for 2018, Hangar 1 chose a new wine to distill into vodka, Napa's Pine Ridge Vineyard's Chenin Blanc + Viognier blend. Unlike Hangar 1's other vodkas, Fog Point is distilled entirely from wine — no grains are used.

"We really wanted to explore distilling a brighter, more light tasting wine to see how the vodka would change," Shoemaker says, explaining that the vodka is distilled to 190-proof, which is then cut with the fog water to half of that, resulting in an 80-proof bottle.

The end result is something of an ethereal experience, says Shoemaker: "I find that when you taste the fog water, it has a little bit of salinity and minerality, which is very interesting because when you look at the lab results of the water, it's very low in actual minerals and much cleaner of any additives than tap water." Shoemaker likens it to the characteristics winemakers say terroir imparts on their vintages.

FogQuest's Bay Area operations are part of the larger work in 10 other countries, including Guatemala, where the company has their largest array of fog collectors in a small village in that country's western highlands. There, dozens of collectors supply water stored in several 1,000-liter tanks for use by local residents.

"People are interested in studying alternative water resources, so that's one reason FogQuest can help a little bit," says Fogliatti. In California, a realistic application would be "to provide some water on the coastal hilltops for reforestation or for drip irrigation," he says.

Or you can mix a cocktail.

Chris Preovolos is a national editor for Hearst Newspaper websites.

More: Listen to Caley Shoemaker and Chris Fogliatti give at talk about the process at Google in 2017