With their juicy, succulent mildness, Walla Walla Sweet onions are among the highlights of many a Northwest summer.
So why does grower Mike Locati sound almost apologetic about them?
“They’re not the prettiest onions in the world, but they’re really good,” the College Place, Wash., farmer says during a break from a typical 14-hour harvest day.
And remember, he adds, they only keep for a couple of weeks once you get them home from the supermarket. “Don’t buy lots of them and try to store them,” Locati cautions. “Buy what you need.”
Even as they work around the clock to bring in this year’s crop, a small group of growers like Locati has its sights set on a sweeter future.
The Walla Walla Sweet Onion Marketing Committee has joined with Washington State University and Oregon State University in a research project to produce a better-looking, longer-lasting onion.
“I see the Walla Walla as an exemplary onion for the sweet onion category,” says Bill Dean, a WSU horticulture professor involved in the study. “It would be a real shame not to make an effort to preserve it.”
What makes the onions so sweet? It’s a combination of high sugar levels and low sulfur, Dean explains.
While it may feel firm, a Walla Walla Sweet is 90 percent water. “There’s a very small amount of dry matter, total solids,” Dean says. “What solid material there is has a real high concentration of soluble sugars, the ones we’re going to taste easily.”
But those sugars don’t do any good if their sweetness is blocked by sulfur, the substance that gives onions their bite. Walla Wallas are low in sulfur both because of the genetic code in the seeds, and the soil they’re grown in, Dean says.
“They’re really mild this year, exceptionally sweet,” says Larry Arbini, a Walla Walla grower.
He thinks that’s partly due to the hard frost this spring, although it was followed by a May heat wave that nudged the first onions into the stores by mid-June, ahead of schedule.
“If the onions get stressed, it seems like it causes them to be milder,” Arbini says. “The yield is down, but they’re more mild.”
Of course, sweet onion growers from Georgia to California, Texas to Maui, will all tell you that their crop is the best.
But there’s scientific evidence that Walla Walla Sweets are superior - or, at least, unique.
In his laboratory tests, Dean says, no other sweet onions have shown as high a sugar concentration as the Walla Walla Sweets, although Texas 1015’s have come close. Vidalias are a little lower on the sweetness scale, which he attributes to frequently cloudy conditions in Georgia.
Wherever they’re grown now, most sweet onions on the market are descended from an apparently Spanish variety first developed in New Mexico, called a Granex, Dean says.
Walla Walla Sweets, on the other hand, trace their roots to Italy. As legend has it, a French soldier named Peter Pieri found the seed on the island of Corsica and brought it with him to Walla Walla in the late 1800s.
Pieri and his Italian immigrant neighbors were soon experimenting with the onions, selectively breeding crops with the qualities they preferred.
In the 1920s, Arbini’s grandfather, John Arbini, developed an early-ripening variety that’s still known as the early Arbini. Today, in selecting his seed stock, Larry Arbini looks for onions with smaller necks, because they tend to ripen better.
“Early onions generally aren’t as big, but they capture that early market,” he says, when people are anxious for the first sweets of the season.
As a result of all the scattered fine-tuning over the years, there really is no single Walla Walla Sweet onion type today, Dean says. There are variations from grower to grower, even from onion to onion within the same field.
“Somebody who likes a really, really sweet onion will get one with a low ratio (of sugar to sulfur) and say, ‘This is really hot compared to the ones I had last week,”’ says Dean.
“When people find out I’m working on a project with Walla Walla Sweets, they tell me that sometimes they get a good bag, and sometimes they get one that’s not as good.”
The seven-year improvement project is designed to change that, by developing a Walla Walla sweet with a more predictable taste, a consistently round shape and a longer shelf life in stores and at home.
“One of the things I would really like to do with the research project is build buyer confidence,” says Locati, who’s among its main supporters.
Growers would like to make inroads into the massive California market, which accounts for only 8 percent of Walla Walla Sweet sales.
And an attractive appearance and ability to stand up to shipping and storage are particularly important for opening up overseas exports, another marketing goal.
In the research project, Dean and his associates are choosing the best onions from various fields to produce seed for future test planting. The weakest of the resulting onions will, in turn, be winnowed out over several more growing seasons to isolate the cream of the crop, which will be continually tested to make sure the sweetness remains.
The key is producing onions with single centers, instead of the double centers you usually see when you cut a Walla Walla Sweet in half. Onions with single centers will be more round, with fewer air pockets that can lead to decay, Locati says.
He also hopes the project will produce a higher-yielding onion seed.
“The yields aren’t high enough to make this thing profitable,” Locati says. “If we had a hardier onion, something that could stand up to the weather and the cold a little better, hopefully yields would go up some and that would help the bottom line.”
Not everyone is excited about the project. Only seven of the 45 Walla Walla Sweet growers are contributing onions for research.
Arbini is not among them. “I’m happy with mine,” he says of his onions. “My grandfather didn’t want to share his seed 90 years ago, and I kind of feel that way now.”
Dean sees it as a matter of survival. While there are 10,000 acres devoted to Vidalia onion production, and 12,000 or more to Texas 1015’s, he says, Walla Walla Sweet growers have gradually dropped from 1,500 acres to 900. “The other guys have grown, while we’re shrinking,” he says.
Concerns about the project are misplaced, contends Locati, like Arbini a third-generation grower.
“There’s been a lot of talk that you’re going to change it, ruin it,” he says. “We’re using our own stock, not taking other onions and breeding them. We’re going to take what we have and try to improve it.”
While today’s Walla Walla Sweets are usually gone by August, Locati dreams of someday being able to keep part of the crop long enough to bring it back over the Thanksgiving-to-Christmas holiday season.
“We could come out with stored onions and probably have a pretty good market for them,” he says.
That’s not just wishful thinking, adds Dean. “I know it can be done,” he says. “We just have to figure out the best way to do it.”
, DataTimes ILLUSTRATION: Color photo
MEMO: This sidebar appeared with the story: SWEET ONION FEST The Walla Walla Sweet Onion Harvest Fest is Sunday from 9 a.m. to 5 p.m. at Fort Walla Walla Park, about 4 miles west of downtown. Activities include food vendors serving onion specialties, cooking demonstrations, arts and crafts booths and kids’ events. For more information on the festival and the onions, including recipes, contact the Walla Walla Sweet Onion Marketing Committee, P.O. Box 644, Walla Walla, WA 99362, (509) 525-1031. Or visit the committee’s World Wide Web site at www.bmi.net/onions/
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