Scent of Raisins

Published online on Sunday, Aug. 30, 2009

Take a leisurely drive through the countryside this time of year with your car windows rolled down. You have to go slow -- if you're lucky, you pass a vineyard and the fragrance of drying grapes fills the air.

Best time is in the evening, when the cooler air presses down against the earth, an inversion layer trapping the aromas of the landscape. You can smell farming when you pass a raisin vineyard by the scent.

Drying grapes into raisins, a step back in time as farmers follow a centuries-old tradition: Grapes are picked and laid out in the sun to naturally dry into raisins.

The process begins in early August when fields are disked and cleared of weeds. The goal is for the earth to dry, all the moisture sucked out, leaving behind parched dirt resembling a fine powder.

Next, in-between the vine rows, just before picking, farmers run a terracer that scrapes the earth smooth in a slight angle toward the south. As the September sun follows a southerly path, the temperatures will be higher and more intense if the dirt is sloped toward this source of heat.

Then an army of workers descend on the fields. They pass out bundles of paper trays, walking down the vine rows. Each thin sheet of paper is about 2 feet wide and 3 feet long. With knives and clippers, they dive under a vine canopy, cut and snip, dropping the bunches into grape pans beneath their working hands.

Quickly they whirl, pause next to an open tray and fling the grapes atop the paper. With a swipe of their hands they spread the grapes over the surface, evenly exposing bunches to the sun. Then again they dive under the vine and begin picking the next tray.

A fast worker can harvest 200-300 or more trays a day, earning a full day's wages in a few hours. Most will start at daybreak; many will stop at the midday heat, then come back in the evening as temperatures dip.

One acre of grapes typically produces 1,000 of these trays or eventually 2 tons of raisins. The trays line the vine row, a side-by-side column of green grapes stretching into the horizon.

Then you wait, 20 to 30 days, depending on the weather, the temperature and the quality of your grapes. Big grapes take longer to dry, poor quality grapes dry faster; cooler-than-normal temperatures (September normal highs average 96 degrees) add days to the process.

If you're fortunate, the sun works as a splendid natural dehydrator, draining moisture from the shriveling berries, curing the meat of a grape into a sweet, chewy mass. If you're not lucky, the temperatures turn cool as a cold front passes through. If you're fatalistic, then a weather change will spell a four-letter word to raisin farmers at this time of year: rain.

With thousands of grapes-turning-into-raisins trays resting in the sun, any moisture can cause mold to grow and rot to fester in the vineyards. A light, fast-moving storm of 1/10 of an inch might not do too much damage, but any prolonged rains over the course of a day or two with rainfall totals above 1/2 inch will cause carnage and destruction.

Why do farmers blindly follow this technique? Because with solar energy, the heat required to dry grapes into raisins is free. Farmers roll the dice and in the month of September, cautiously monitor the west for dark clouds. They, as their ancestors, have been "green" for generations; no artificial heat required; all sun powered, and we leave a very small carbon footprint. Most farmers simply call it the old-fashioned way.

(Note: The golden raisins you find in stores and bakers often use to highlight their recipes are highly processed, dried in tunnels, using heaters and sometimes sulfur. Almost all other raisins are made from green Thompson seedless that dry into the dark "tanned" treats.)