Sonoma Crush: On the Frontlines during Harvest Season

Editors note: We are deeply saddened that California fires have damaged many vineyards. The Kendall-Jackson winery family home was destroyed in the Kincade Fire in October. Our hearts go out to everyone affected. 

Sonoma, California isn’t known for its nightlife scene—in fact, locals have dubbed it ‘Slo-noma’ due to the fact that many bars and restaurants shutter at around 9 pm each night. But during crush—the time of year ripe grapes are harvested from vineyards—the activity in the valley is non-stop.

At Kendall-Jackson, the process begins several weeks before harvest, when vignerons (aka grape growers) roam the rows with 5-gallon buckets and pick random samples of grapes to test. They test for the brix (the sugar level inside the grape that will determine the wine’s alcohol level), the acid and the Ph. Typically, the first test is just that—a starting point for the grapes to be checked more frequently as they mature. “We have the vineyard guys sample the grapes and decide when they’re ready for our winemakers to focus on tasting the grapes for the correct flavors and, additionally the tannins and their maturity for the reds,” says Randy Ullom, Winemaster at Kendall-Jackson Winery. The grapes will be tested weekly, twice a week, or every other day based on their flavor. When the grapes are where the winemaker wants them to be, they’ll request for a block or a portion of the vineyard to be picked.

While some vineyards have rows wide enough for machines to harvest grapes from them, many vineyards are picked by hand. That’s when Sonoma’s action after dark starts hopping. Starting between 10 pm and midnight, the vineyards flood with workers wielding pruning shears and plastic bins. They work until dawn. There are a couple of reasons grapes are harvested at night, and none of them are about being stealthy. One reason is that warm daytime temperatures can change the sugar composition of grapes and picking them at night keeps the sugar levels stable due to much lower temperatures. The other is that it’s easier on humans than working under direct sunlight. The fields aren’t dark, however. Stadium lights are brought out to the vineyards, spilling enough illumination over them that it looks like daylight.

Estate Vineyards at Kendall-Jackson

Timing is crucial. As soon as the grapes are picked, the clock starts ticking. “We want to get the grapes to the winery as soon as possible,” says Ullom. “When you’re after quality, you want your grapes to be close to where they’re being processed. For Kendall-Jackson, in some locations, we can process our grapes within 30 minutes of when we pick them.” Within a couple of hours, the grapes are transported to the winery, where they’re run through an auger, crushing and possibly destemming the grapes before the juice and skins are placed in a steel tank. They’re then dosed with yeast to begin the fermentation process that turns grape juice into a Bacchanalian beverage.

It’s almost as if there’s something intoxicating in the air itself, because from August to October, Sonoma rocks with winery dinners, harvest festivals and fairs, wine tastings and even workshops where visitors can experience crush for themselves. For these types of events, winemakers will give visitors a tour of the vineyards, where they’ll actually have the opportunity harvest grapes before going to the winery to see the production and aging process. For a sense of scale, during crush, just one of Kendall-Jackson’s wine production facilities can process several hundred tons of grapes per day. Each grape truck holds between 20 and 22 tons of grapes.

Some wines are fermented with the grape skins in the tank, while others are not, depending on the varietal and desired outcome. If skins are present, the wine to be is pumped over twice a day to keep things circulating. The skins are removed after 7 to 10 days, when the secondary or malolactic fermentation is done. In simpler terms, it just means that the tart malic acid found in the skins is converted to the softer tasting lactic acid with the use of specific yeasts, leading to a fuller mouthfeel. The wine is then transferred “to age gracefully,” as Ullom says, in French or American oak barrels for anywhere between 6 to 15 months and topped off periodically. The whites are topped off monthly. Additionally, the Chardonnays are stirred on their lees once or twice a month by hand.  The red wines, depending on the year and need, are topped off monthly or every two months.

The barrels are sorted into lots and racked. There are roughly 400 lots, and Ullom has to taste his way through them all. “It’s all about becoming one with the wine,” he says. “As you taste through the lots, it’s like painting a picture. You’re putting the blend together in your head.” Once Ullom hits upon that ideal blend, somehow balancing all those factors and variables that can change from year to year, the wine is ready to be bottled and labeled. “Blending is about creating something the consumer likes and that will bring a smile to their face,” he says.

It’s remarkable to consider how much time, energy and resources are devoted to produce the bottles of wine that grace our dinner tables and accompany our events, whether it’s raising a glass at a wedding or sipping something cold on the porch on a hot summer day. All year, grape growers are preparing for crush, an event that ultimately lasts only a few weeks, followed by celebrating another successful harvest. Every year is different, though, and like any type of farming, there’s risk and uncertainty when it comes to growing grapes. Sonoma’s oldest festival, the Valley of the Moon Vintage Festival, kicks off with the grapes being blessed, because for all the human effort involved, sometimes it takes some divine intervention to produce the perfect bottle of wine.

Rebecca Treon is a Denver-based freelance food, travel, and lifestyles writer who has written for publications like 5280, DiningOut, American Bungalow, ReignDenver HotelThe Coastal Table, the Huffington Post, Tasting Table, Food 52, Time Out, BBC Travel, Livability, The Cape Cod Travel GuideEdible Cape Cod,Edible Denver, Edible Lower Alabama, Alabama Journey, The Denver Post, and DRAFT magazine. She is the proud mother of two tiny globetrotters.