(Economist) - High-tech winemaking: Technology has already made poor plonk a thing of the past. What can it do to improve the world’s finest wines?

IT IS five o’clock in the morning at the height of California’s harvest season, and the full moon hanging low over the Carneros hills bathes the chardonnay vineyards in cheese-yellow light. A crew of 30 Mexican grape-pickers, wearing headlamps and orange safety vests, races down the rows in silence, deftly severing the bunches with crescent-shaped knives and dropping them into plastic bins. They have to work fast in the cool night air, taking a few seconds to strip each plant, because within an hour it will be too warm to harvest the fragile grapes. “They are skilled, more than they’re given credit for,” says Towle Merritt, a general manager at Walsh Vineyards Management, the viticulture firm that employs them. 

Harvest night has also arrived at a cabernet sauvignon vineyard 36km (23 miles) to the north, in the heart of the Napa valley. But here there are no artificial lights, portable toilets or on-site sorting teams. Instead, a single driver pilots a 3.65-metre (12 feet) high arch-shaped tractor towards the end of a row. The earth below is highly uneven, but the vehicle’s massive wheels, each with its own gyroscope and hydraulic controls, extend, twist and tilt to keep the cab perfectly level as they line up on either side of the vines. The driver launches the tractor straight along the top of the row. The engine whirrs, branches crackle and leaves fly into the air as he zips along.