Raisins: New wrinkle in state agriculture?

Washington farmers already grow some of the finest wine grapes in the world. Could they also grow some of the finest raisins?

That is not out of the realm of possibility, according to Carter Clary, an assistant professor in the Washington State University department of horticulture and landscape architecture.

Clary is a leading expert on dried fruits and vegetables who works primarily on improving the drying and processing of potatoes, strawberries, raspberries and blueberries. He recently was honored by the International Organization of Vine and Wine for a book he co-edited with Vincent Petrucci, professor emeritus of viticulture, while he worked at California State University-Fresno. “A Treatise on Raisin Production, Processing and Marketing” is a glossy, four-color, grower-friendly guide to raisin production around the globe.

“I’m not saying raisins could be the next star crop of Washington state,” Clary said. “But we could grow raisins here.” He already has two small plots of raisin grapes planted outside Walla Walla. Water and soil conditions are perfectly suited for raisin grape production, but the researcher said cold winter temperatures are an issue.

“The traditional Thompson seedless grapes grown for raisins in California do not winter well here,” he said. “A heartier variety, like the Black Monukka, winters well, produces a very sweet, rich fruit and would do just fine.”

Clary said Washington probably never would produce more raisins than California growers, but it might be able to grow better ones.

“The Washington wine industry is based on producing very high quality, high-end wines aimed at niche markets,” he said. “A grower could concentrate on producing a high quality, gourmet raisin and have the same kind of success.”

Raisins were one of the first fruits to be preserved and stored for later consumption, so old they are mentioned in the Bible. They are grown primarily in the United States, but also in China, Turkey, Iran, India, Chile, Australia and South Africa. Raisin grapes account for approximately 7.6 percent of the total world grape production.