Military tool helps make classier wines
Ground radar gadget tested in California wine country
By Marsha Walton
(CNN) -- Grapes and geophysics may go together as smoothly as grilled vegetables and a fine Merlot.
Scientists at the University of California at Berkeley are using ground penetrating radar (GPR), a tool better known for its military uses, to help winemakers create tastier, more uniform wines.
"GPR is an electromagnetic signal that travels in the ground. What we do is try to understand how fast that signal travels and that tells us a lot about the moisture content of the soil," said Susan Hubbard, a hydrogeophysicist at University of California, Berkeley, and staff scientist at Lawrence Berkeley National Laboratory.
Understanding soil moisture is a critical part of the art and science of winemaking. Cabernet Sauvignon and other red wine grapes prefer drier soil. Chardonnay and other white wine grapes do better in moist soil. But growers say the timing, and the amount of water given to the vines can make the difference between an average and an outstanding crop.
"We also have a timing issue," said Daniel Bosch, director of Napa Valley Vineyard Operations for Robert Mondavi Winery.
"You don't want to pick grapes and have some of the earlier ripening mixed with the higher ripening, because you might get a blend of average. You want to pick all of them at their optimum maturity," Bosch said.
The GPR technology is being tested at the Robert Mondavi and Dehlinger wineries in California's Napa and Sonoma counties.
The test device is a bit larger than a vacuum cleaner. It includes a transmitting antenna that sends the electromagnetic signal into the ground, a receiving antenna, and a gauge which determines how often the measurements are taken.
A 12-volt battery provides the power, and the information is recorded on a laptop computer.
"This setup we've been using is helpful for us to understand what kind of spacing and frequency of data we need," Hubbard said.
She said it's probably three years before the technology is widely available to grape growers.
If that becomes the norm, grape growers will be able to decide how much to irrigate, and will have precise enough information to water row by row, even vine by vine. In that way, chances are greater that more grapes will be picked at the peak of flavor, Bosch said.
Hubbard said the radar technology could eventually work to improve the growth cycle of other crops, and could make far more efficient use of water, especially in drought-prone areas.
"I do think you'll see better wine as this technology tends to be used more and more," Bosch said. "But you're never going to take the art out of winemaking."