CALEDONIA, Minn. - Enormous stacks of white-oak strips cover the surrounding hills. In the cavernous building below, a cacophony of saws and other milling machinery seeps through even the sturdiest of ear protectors. Up the driveway inside a small office, a soft-spoken man talks on the phone, barely audible over the snoring of a dog.

The sights and sounds of your typical lumber mill? Well, yes and no. The work at Staggemeyer Stave is not out of the ordinary, but the end product most assuredly is: wood slats (staves) that will become barrels, imparting flavor and depth to some of the world's best wines and spirits.

"White oak is really good at holding liquid and not absorbing it," said Mike Staggemeyer, owner and president of the mill. "The wine extracts flavor from the wood, and the winemakers like the flavor it imparts."

Which is why there might well be a "Minnesota flavor" to that Murphy-Goode chardonnay or Jack Daniel's whiskey you'll be sipping this weekend.

French oak is the most renowned in the wine world, but its American counterpart has been gaining favor for years. French oak imparts more "woody" extract into a wine but little other flavor, while American oak has a very small amount of wood extract but a larger flavor impact (think vanilla and coconut). Along with this area, Missouri, Pennsylvania and Virginia are the prime sources of American oak.

Minnesota oak might be even more popular overseas than on these shores. Staggemeyer ships staves to Australia, France, Portugal, Spain and Hungary as well as to California. Some French winemakers prefer Minnesota oak to the native stuff for their pinot noirs, and the website for Algodon Wine Estates in Argentina has this to say: "Minnesota oak barrels ... give a roasted nut nose, with a long, warm, integrated finish in the palate."

And it all starts within 150 miles of this southeastern Minnesota town, in forests that are generally about 40 percent white oak. "Our cold winters slow the growing process, so the rings on the wood are tighter, and that's what they want," Staggemeyer said. "They get so tight you almost can't count 'em."

Not up to capacity

Staggemeyer actually could process more wood if he could get it. At full capacity he could employ 30 mill workers rather than the 13 who now work four 10-hour shifts a week.

"Other markets drive this. With the housing business down, the lumber business is down," he said. "The biggest problem is that everybody is cutting down black walnut right now. There's also a shortage of loggers because people aren't following in their fathers' footsteps.

"And our woods are mostly red oak and white oak, but if a guy can't sell the red oak, he's not going to cut down [anything]."

Still, every week 17 semi-truckloads of 80- to 150-year-old oak trunks arrive at the plant. After de-barking, the trunks are cut into quarters on a standard mill and inspected for defects.

About half of the logs have sap removed. "The wine people want all the sap off, but the bourbon people actually like to see some of that," said foreman Blake Schuldt.

Eventually, the wood is cut into staves, which vary in length, width and depth depending on the destination and intended use. Whiskey barrels, for example, traditionally hold 52 gallons, U.S. wine barrels 60 gallons and Australian wine barrels 70 gallons.

Another difference: The wine staves age outdoors for 24 to 36 months, while the whiskey staves go South almost immediately.

Staggemeyer does not roll out the barrels; that happens at cooperages near the wineries and distilleries. "It's a freight issue," said Staggemeyer. "You want to put the barrels together as close as you can to where they're going to be used."

And boy, do they get used. Wineries don't want their competitors to know exactly which barrels they're using, said Duane Wall, vice president of Nadalie USA, a Napa-based cooperage, but "a lot of big-volume producers and a lot of high-end producers use Minnesota oak regularly.

"One person will swear that Minnesota is a godsend to pinot noir or cabernet or chardonnay, and the next person will look at it completely different. It's more about stylistically what the winemaker will want, so it's across the board."

Bill Ward • bill.ward@startribune.com Read Ward on Wine at www.startribune.com/blogs/wine.

Stave minutiae
• The mill opened in 1957. Staggemeyer's father Norbert bought it in 1967.
• Until a 1995 flood, the office was next to the mill. "We came out here, and the coffeemaker floated out of the office," said Mike Staggemeyer. "So we moved it up the hill.
• Not a bit of wood is wasted. The chips and bark waste go to paper mills — white oak makes high-quality cardboard — and the sawdust to farms. "We just about have a waiting list from the dairy farmers," said foreman Blake Schuldt .
• Barrels generally are used at wineries for about eight years, then show up at your local garden center, cut in half. The wood's impact on the liquid becomes neutral after two vintages, usually.