“Windy Oaks Estate” - Finest Pinot Noirs and Chardonnays from the Central Coast in California

Having experienced several years of yield shortages, Jim Schultze, owner of Windy Oaks Estate in Corralitos, began to seek technology solutions that fit within their sustainable, minimal intervention approach to winemaking. His winery covers 12 ha and belongs to the appellations of Monterey and Santa Cruz Mountains.

After discovering Agrothermal Systems (www.agrothermalsystems.com) in an industry magazine, Jim Schultze met with CEO Marty Fischer at a tradeshow, who was able to show him the AgrothermXT machine first hand and gave a good sense of the technology's potential.

“I was intrigued with the idea of Agrothermal Systems in that it could maintain and improve wine quality while increasing yields. The pest control aspects of the technology also meant that I could potentially reduce pesticides or possibly even chemical free farming.”

Jim Schultze then called a number of Agrothermal Systems current customers and concluded that, “If Thermaculture works the way other people have found it to work, then even with a 10-15% increase in yield we'd have a realistic payback period of about a year.”

According to Marty Fischer, CEO of Agrothermal “Jim and I really hit it off. It's nice to see a multi-talented entrepreneur who just does everything the way it should be done and approaches the decision-making process with an open mind.”

Philip Goodband and I visited Windy Oaks along with our CFO Rich Griffith before he bought the machine. When we tasted his wines they were all impressive. It'll be a challenge to see if our heat treatments can improve upon them.

Schultze decided to purchase an AgrothermXT machine and begin treatment on 4 blocks of Pinot Noir and Chardonnay. There was a brief learning curve but, Jim and his team found the machine very straightforward. They treated the blocks during flowering, and up to veraison as Agrothermal had recommended. “I perceived a visual difference in terms of cluster size for the heat treated rows vs. the non-treated rows... the heat treated clusters were visibly fuller,” Jim observed.

At harvest, Schultze saw increases in yields between 12-31%, with an average of 21%, performing at and above the level they had hoped, “Just that increase in production alone justifies having the machine. According to Fischer. I walked the blocks a week before harvest and it was real clear that the treated bunches were bigger and fuller. Jim's increase is pretty much what we experienced at most other vineyards this year. What's great is the return on investment for Jim. At $50 plus a bottle, this kind of increase means a lot to Jim's financial success and that is very nice to see.”


At the beginning of February in 2017, Jim Schultze and his winemaking team met with Philip Goodband, Master of Wine, and Marty Fischer to conduct a blind tasting of the different Pinot Noir and Chardonnay blocks vs. control. The Thermaculture trials were conducted on 0,5 ha blocks with heat-treated and controls using identical root stock and clonal selections for each pair of wines. At harvest, the fruit was put in separate bins, given the same treatment with partial or whole cluster fermentation using the same yeast.

“The differences were clear. At this stage the wines are very early in their life, but you can already see the direction they are headed. It was 100% consistent, we all agreed that the heat-treated wines were more fruit-forward, with a richer mouthfeel and a nice finish. I was surprised at the consistency across the people tasting and in the wine from our different blocks. To be consistent across all the different blocks, it's not a coincidence, I'm convinced that the heat treatment has a specific impact on flavor.” Schultze concluded.

Goodband added “To taste pairs of test and control wines carefully vinified using more than one winemaking technique, and to note the enhanced characteristics across all heat-treated wines further reinforced my view that Thermaculture definitely aids terroir expression.”

Marty explains “A lot of people believe these kinds of increases in yields will reduce wine quality, but we have seen the opposite. The heat treatments shock the vines and we get higher levels of phenol and antioxidant as a result. We have seeing as much as 35% higher yields, and the resulting wine is consistently preferred during blind taste tests vs. control.”


Recording an average 21% increase in yields, and enhanced wine characteristics from this crop, Jim Schultze is convinced that Thermaculture really works. For the 2017 season he plans to use heat treatment throughout the 6,5 ha vineyard in Corralitos, and will be testing one whole block without the use of any pesticide sprays. Schultze plans that If the test works well using no spray materials, we will certainly build on that and push the envelope to find the point where we can minimize the use of sprays throughout the vineyard... It would be great to have the pesticide and fungicide benefits in addition to yield benefits.

According to Fischer, the company was originally focused on pest control, but found the capability to control pests challenging, especially in cooler wetter climates. “After several seasons of trials, we are very close to two protocols that seem to work well in most climates. These are being tested in New Zealand. If they work well there, they should work everywhere in California.”

Looking into the future, Jim Schultze sees many benefits, both tangible and intangible, that he hopes to take advantage of. Increasing yields, decreasing pest control, and safely drying off crops after rain are all a part of the sustainable approach the Windy Oaks brand strives to achieve. Jim concludes:

“Sustainability is really important and gaining more and more visibility. The heat treatment with AgrothermXT could be a great part of that story and one that consumers would be very responsive to. It will be a part of our future promotional activities if successful.”

Jim Schultze

Owner and Vintner of Windy Oaks Estate (Corralitos in California / USA)