Growing & Winemaking

 

How Wineries Use Vineyard Technology

March 2017
 
by Andy Starr
 
 

A Google search for the exact phrase “wines are made in the vineyard” produced 40,600 results, making it one of the industry’s mantras, along with “our Chardonnay is buttery” and “I thought we’d be cash-flow positive by now.” All overused, yet accurate.

Since much of winery success and wine quality is based on grape quality, I interviewed several winemakers and viticulturists about what they currently do in the vineyard to enhance wine flavor and assure consistency from year to year. They shared with me what data they collect, cropping levels, harvest criteria and advanced technologies employed.

Rodney Strong Vineyards
Since 1959, Rodney Strong Vineyards has been one of Sonoma County’s premier wine operations, producing 850,000 cases annually under the Rodney Strong and Davis Bynum labels. The winery owns 1,200 acres of vineyards exclusively in Sonoma County. While Rodney Strong purchases two-thirds of its grapes, the grape contracts provide viticultural control. Both winemaker Justin Seidenfeld and winegrower Ryan Decker shared their approaches to growing and winemaking.

Crop level decisions: Seidenfeld and Decker stated that they no longer look at tons per acre, measuring pounds of fruit per vine instead. As Decker notes, while “yield per acre is easy to trace, pounds per vine speaks to what the vineyard is doing.” They aim for a weight/vine target specific to the vineyard location and varietal; for example in a Sonoma County Pinot Noir block, the target is 4 to 6 pounds per vine, depending on the clone. They believe the old “tons per acre” method leads to under-cropping vigorous vines and over-cropping the weaker ones, leading to variable grape quality and a wide range in vine health within the vineyard.

Decker noted that targeting level fruit weight per vine makes the grower work to equalize vine vigor to achieve the weight per vine target. He adjusts irrigation, fertilization and cover crops to achieve more uniform vine health. This increases consistency and quality and avoids overworking the vineyard. Decker said that following this protocol means the only way to increase fruit yield is to increase vine density when replanting.

Vineyard health measurements: Ryan stated that his team does petiole sampling at bloom and at véraison to measure the following nutrient levels: nitrogen, potassium, magnesium, calcium, boron and zinc. He added that they may also look at chlorides if the soil is known for high salinity.

Harvest decisions: Seidenfeld seeks “a physiologically ripe grape, so measuring pH and TA is almost as important as Brix.” Ideally, all blocks and all vines would have the same physiological ripeness. He tries to avoid hard tannins from underripe fruit or chalky tannins from overripe fruit. If it’s overripe, “It’s just desiccating, so everything is out of whack.”

Advanced technology: Seidenfeld believes that in striving to improve quality, “Technology is the helping hand.” An example is his use of selective mechanical harvesting and field sorting. Machine harvesting allows him to pick at night and bring in cooler fruit, which improves wine quality and saves considerable energy in cooling warm grape must. In addition, it helps to avoid any labor-shortage issues. The Pellenc harvester then field sorts fruit, separating ideal berries from raisins. Decker stated that the sorter unit “has replaced six or seven people on an incline conveyor and does a better job.”

Additional examples include the extensive use of VineView’s aerial imaging and spectral mapping to identify areas of high and low vigor, which then directs their efforts to balance the vineyard. They also use advanced methods of monitoring vine water status via evapotranspiration and stomatal conductance measurements. Looking to the future, they will add continuous soil moisture monitoring to their vineyard weather stations and investigate other remote-sensing devices to be able to keep tabs on their vineyards 24 hours a day.

Kosta Browne

Kosta Browne produces elite Sonoma County Pinot Noir and Chardonnay under the Kosta Browne and CIRQ brands. Started 20 years ago by partners Michael Browne and Dan Kosta, Kosta Browne owns 80 acres of vineyard split between Cerise and Keefer Ranch and purchases fruit from 49 additional growers. As with Rodney Strong, I was able to get the perspective of their viticulturist and their winemaker, Sam Ausburn and Nico Cueva, respectively.

Cropping level: Ausburn noted the importance of the vine being in balance with the fruit it is supporting. The vine needs proper nutrition to support the canopy throughout the growing season. He observed that a deficiency will cause a late-season vine weakening or crash. Kosta Browne will balance out vigor variations within the vineyard by pruning or fertilizing differently.

Vineyard health measurements: Cueva collects data on all grapes, purchased or owned. He analyses potassium levels, especially on Chardonnay. Having built a substantial database of Chardonnay potassium levels, he now watches for a drop-off that indicates, “You need to get ready to pick.” While not everyone can afford the advanced equipment and methods that Kosta Browne uses, Ausburn advised small growers to buy some inexpensive moisture probes to identify where the vineyard is drying out and collect data at least weekly.

Harvest decisions: As Rodney Strong does, Kosta Browne emphasizes bringing fruit in at a cool temperature and sorting. Cueva explained, “We hand-harvest all fruit at night and sort everything at the winery,” starting at midnight, and bring the grapes to the winery between 5 a.m. and 6 a.m. Either he or Ausburn show up at the beginning of every picking, providing instructions and inspection at more than 50 picks per harvest. While this is a huge time commitment, they believe it pays off later with better wine and fewer winemaking problems.

The hand-harvested grapes are sorted using a Key Industries shaker table and a Pellenc optical sorter and destemmer, which Cueva noted “has exponentially increased our quality.” They also will use cluster sorting for lots where whole-cluster ferm entation is done. Both Cueva and Ausburn recommended that the winemaker spend time being selective during picking—or, as Cueva put it, “have an OCD standard for picking. There is less need to sort if you can be on it at harvest.” Essentially it builds quality into the process with cleaner ferments and better wine.

While both Ausburn and Cueva think these are great tools, they believe the best tool is still human eyes, walking through the vineyard and looking at vine canopy and fruit. Cueva takes spending time in the vineyard a step further, pointing out that one of his best vineyard “tools” is simply a strong, experienced cellar team. The low attrition rate among production staff allows him to spend more time walking the vineyards all year long, which results in better quality. As a winemaker, he understands that he can have a greater impact on quality in the vineyard than in the cellar. What impressed me was his deliberate linking of creating a good workplace with low employee turnover and improved wine quality.

Advanced technology: Kosta Browne uses NDVI (normalized difference vegetation index) aerial imagery to analyze vineyard canopy growth and block variation. Cueva talked about the goal of dry farming if at all possible, and Ausburn believes that deficit irrigation plays an important role in fruit quality. While Ausburn uses pressure bombs, he is impressed with new water-management technology developed by Fruition Sciences, noting that their “sensors have given us the ability to look at the vine more closely. We are able to make more precise irrigation decisions.”

Cueva explained that to minimize the negative effects of the time delay from harvest to processing, his people are now experimenting with sorting fruit in the vineyard, cooling it with dry ice and then dumping it directly into a fermentation tank.

Kendall-Jackson Winery

For the past 25 years, Randy Ullom has been the winemaster for Kendall-Jackson Winery, the flagship of Santa Rosa, Calif.-based Jackson Family Wines. Producing consistent, high-quality wines at a at high volume is a monumental challenge complicated by many varietals, regions and price tiers.

Vineyard measurements: Ullom said simply, “It boils down to management of irrigation and vine balance.” Pressure bombs, plus in-ground and in-vine sensors are the tools Kendall-Jackson uses to monitor and maintain moisture levels at an optimal point to get to an ideal berry size.

Cropping level: Ullom believes that a balanced vine is what everyone should be seeking. So beyond irrigation, he recommended paying attention to canopy management and fruit thinning at véraison. A green fruit drop is easy, but his crew members will also pull off overripe fruit to narrow the Brix range. He believes wineries should be hands-on when asking a grower to do leaf pulling, shoot thinning or drop crop. “Be there and do it with them for a little bit. Being hands-on and showing what you want is worth its weight in gold.”

Harvest decisions: Like the others, Ullom said the ultimate harvest decision is the taste—that you pick on flavor, not on numbers. He views Brix as an important indicator and values pH and TA as well. He states, “pH tells you when you are getting close and what is going on in the berry.” For example, if pH is starting to bump up too fast and TA falls rapidly, the berry may be falling apart internally. In some vineyard blocks, Kendall-Jackson will pick 100 berries and measure diameter, moisture and weight.

Mechanical vs. hand harvesting: Kendall-Jackson’s most significant change has been toward night harvesting, regardless of whether fruit is hand or machine picked. In Ullom’s view, hand harvesting at night improves the working conditions of the pickers, as they avoid the hot sun of late summer, and improves the quality of the grape picker’s life. It also uses less energy by picking essentially “refrigerated grapes.” Machine harvesting at night is always combined with destemming and sorting in the vineyard on the harvester itself. Crew members use both Braud and Pellenc harvester/destemmer/sorters and end up with grapes that are conceivably ready to go to the tank—or, as Ullom said, “The grapes are clean and looking like caviar.” Once they started using these automated systems, it “was a black-and-white difference, and we jumped on it” for wines selling from $13 to $125 per bottle.

Advanced technology: Aerial imaging of vineyards is used heavily, in particular NDVI technology. Ullom recommended that any vineyard owner should have at least one image taken per year, as it offers a quick way to see rich, weak and average vines and soils without walking every row. He has images taken in spring, mid-summer (close to véraison) and just before harvest.

In summary, many tools are available to grapegrowers and winemakers to measure and manage vine health and grape quality. Some are leading-edge technology like EVI aerial imaging, and some as simple as having a great cellar crew that lets you as the winemaker spend time in the vineyard.

 
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