Reprinted with permission from the Idaho Wine Commission, November, 2021

Idaho’s 2021 Grape Harvest: Bright and Intense—Like Idaho’s Summer

Intense Heat

Temperatures soared across the Pacific Northwest in June this year, and the heat wave lingered in Idaho for a good chunk of the summer. National Weather Service data showed the Treasure Valley in southwest Idaho—home to two of the state’s American Viticultural Areas (AVAs)—had the hottest summer on record. And the heat affected the Lewis-Clark Valley AVA in the northern part of the state as well.

“During bloom time, it was about 100 degrees, so bloom went really fast,” said Vince Hewett, assistant winemaker at Rivaura Vineyard near Julietta, Idaho. He said they saw consistent 100-degree weather for close to a month in June and July.

When temperatures rise above 95 degrees, vines slow down and go into heat stress mode to conserve their water. This slows down photosynthesis and slows the development of sugars in the fruit. The answer is more water, and Idaho grape growers pulled out all the stops.

“Early on in the growing season, when (the vines) were just getting started, we gave them all the water they needed and could want,” Hewett said.

The hot weather meant budbreak happened earlier this year for some vineyards, and harvest started and ended sooner. For Skyline Vineyards outside Caldwell, Idaho, Viticulturist and Vineyard Manager Jake Cragin reported harvest began in late August this year, nine days earlier than in 2020, and was wrapped up in October—unhampered by any early frosts.

Smaller Berries, Smaller Yields

Idaho vineyards reported yields were down slightly due to the heat.

Skyline’s yields were down 12 percent overall, according to Cragin. Mike Williamson of Williamson Orchards and Vineyards reported yields were down on young blocks of vines. “They seemed to struggle with the heat more than the older vines,” he said.

Martin Fujishin of Fujishin Family Cellars agreed the impact was inconsistent. “Some of our red varieties have a very, very light crop load. And some of the white varieties or some of the earlier reds have a much heavier crop load. So, we have a lot of variability in the size of crop coming in for each variety, which is kind of the name of the game on a hot year.”

Intense Color and Flavor

There is a marvelous silver lining for Idaho winemakers.

“We had the same number of clusters we would for a normal year, but the size of the berries on those clusters was much smaller. And that means more skin contact for the wines, which means more color intensity, and in many cases, more flavor intensity,” Fujishin said.

Vince Hewett from Rivaura said winemakers like to call it a “higher skin to juice ratio” which means the surface area of the grape is higher in proportion to the contents inside. “That’s where all the yummy flavors and aromas are at in the grape,” he added.

Hewett said because of the smaller berries, Rivaura was seeing some of the best fruit quality they’ve ever had. “Tasting at the press, the wines are tracking to be an awesome vintage,” he said.

Fujishin summed it up. “A lot of the work is already done for us,” he said. “We’re going to have bright, intense flavors, and our job is not to mess it up.”

Future Knowledge

Moya Dolsby, Executive Director of the Idaho Wine Commission, praised how growers across the state responded to this summer’s heat. “Idaho’s grape growers are resilient,” she said, adding the issue of warmer temperatures is not going away.

“This season gave us a wealth of knowledge about growing grapes in these conditions,” she said.

Hewett of Rivaura agreed. “It’s something we’re going to have to face in the future.”

Reprinted with permission from the Idaho Wine Commission, February, 2021

It all starts with the grapes.

Well, we better start with the beginning. Idaho is considered, by some, part of the new frontier of grape-growing areas in the United States. The first grapes planted in Idaho were actually grown in Lewiston in 1864.

John H. Thorngate Ph.D., formerly a professor at the University of Idaho, now Applications Chemist, Research & Development, Constellation Wines U.S., says, "in Idaho we're the oft-forgotten 'other' state in the Pacific Northwest.” Which is rather ironic, considering that the first wineries in the Pacific Northwest were located in Idaho, and that Idaho had a nationally renowned wine industry until Prohibition, as in other regions, closed the industry down.

Two French, Louis Desol and Robert Schleicher, and one German immigrant, Jacob Schaefer  planted grapes in Idaho before any were planted in Washington or Oregon. They were winning awards around the country before Prohibition took a debilitating toll on the industry and brought production to an absolute halt. National prohibition, which followed state prohibition in 1916 and lasted until 1933, took its toll on the wine regions, its growers and makers, and it wasn’t until 1970 that wine grapes were again planted in Idaho, this time along the Snake River Valley in the southern part of the state where most of the state’s wineries are located.

It was in the Snake River Valley that Idaho’s first American Viticultural Area (AVA) was approved in April 2007. Southwestern Idaho currently has the highest density of vineyards and wineries and includes the Snake River Valley AVA, which covers over 8,000 square miles with comparable latitudes to many famous wine-growing regions in the world. The immense size is a great advantage, allowing for tremendous growth. The approval of the AVA was a vast undertaking and has truly helped propel the industry, gaining attention around the world.

The story behind Idaho wine: location, location, location.

From a purely geographical standpoint, area vintners insist, southern Idaho offers ideal growing conditions. Vinifera, or wine grapes, actually thrive in this distinctly four-season climate, The characteristic cold winters, which might at first seem a disadvantage, are in fact quite conducive, allowing vines to go dormant, to rest and conserve important carbohydrates for the coming season, while ridding the plants of bugs and discouraging disease. In addition, the region's summer combination of cold nights and warm days serves to balance grape acids and sugars favorably. In the 30*-40* diurnal temperature variations typical of this higher elevation—swings from 1--* to 65* are common—sugars remain high , nurtured during the long day by the abundant sunshine, while acids are maintained at favorable levels by comparatively cool evenings. These natural acids, important for the wine's taste and longevity, can be difficult to maintain in, for example, the warmer California climate. Adequate sugar, on the other hand, is often the obstacle in Oregon, where early rains absorbed by the grapes and vines in the final stages of ripening dilute the fruit's natural levels of the substance. Because such potentially ruinous precipitation is also responsible for assorted other agricultural woes, including mold and rot, the Snake River Valley's lack of rainfall is considered a plus; here, water is one element that can be controlled by the grower through irrigation, according to calculated timing.

Harvesting Good Times

The Idaho wine industry has been a steadily growing community for the last 30 years with remarkable growth in the past decade. With 38 wineries in 2008, Idaho is now home to more than 60 wineries, with over 1,300 acres of grapes planted. The industry will continue to grow as national wine consumption increases, as well as Idaho's grape growing potential. Idaho wines have been discovered across the country ranking 22nd in the nation. The Idaho wine industry is just in its infancy and is expected to see remarkable growth in the next 15 years. It is just coming into its own, receiving a great deal of recognition, and winemakers and growers are learning as they go while making great wine along the way.