Month: September 2021

By: Becky Garrison   

The United States Department of Agriculture defines a cover crop as “a crop generally recognized by agricultural experts as agronomically sound for the area for erosion control or other purposes related to conservation or soil improvement.” The USDA National Resources Conservation Service website offers this concise explanation of the multiple benefits of implementing a cropping system. “They can prevent soil and wind erosion, improve soil’s physical and biological properties, supply nutrients, suppress weeds, improve the availability of soil water and break pest cycles along with various other benefits. The species of cover crop selected along with its management determines the benefits and returns.” 

  While many vineyards have been utilizing cover crops for years, are they maximizing the poten-tial of this agricultural practice? During the 2020 Oregon Wine Symposium, held virtually from February 16 to 19, 2020, two panels delved into the nuances of what defines high quality soil and the role cover crops play in generating organic soil, focusing particularly on how to best utilize cover crops in the vineyard setting.  

  At the first panel, “Soils and Cover Crops: Back to Basics,” James Cassidy, Senior Instructor in Soil Science & Sustainable/Organic Agriculture at Oregon State University, opened with a short presentation on Soil 101. He described soil as “rotted” rock and decomposed organic matter. Next, he broke down soil into soil solids (mineral 45%, organic 5%) and pore space (air 20-30%, water 20-30%). Carbon from the atmosphere and energy from the sun transform these materials into soil courtesy of the billions of organisms present in a single pinch of soil.  

  “Internalize the idea that soil is habitat for everything that is alive on this planet,” Cassidy said.  

  During irrigation, rain or another precipitation event, gravity pulls the water into the soil’s macropores. As water flows through these macropores, it sticks in the micropores inside the soil and eventually fills with water. Then the soil drains, and there’s air in the soil.  

  “When the soil is draining, it’s actually breathing,” Cassidy said.  

  The rate at which water moves into the soil is impacted by various factors, including soil type (texture structure, aggregate stability, hydrodynamic characteristics), topography and morphology of slopes, flow supply (rain intensity, irrigation flow), and the initial condition of the soil’s humidity.  

  Currently, on Earth, a hectare of productive soil is lost every six seconds. While farmers can’t change their land’s soil type or topography, they can manage for stable aggregates, a wide pore size distribution structure and minimized compaction. Well aggregated, stable soil pulls in water. This means the water goes deeper into the soil instead of producing runoff, which carries away the small particles and organic matter that hold nutrients in the soil.  

  For every 1% increase in organic matter, soil can store up to 25,000 more gallons of water per acre. In Cassidy’s estimation, cover crops represent the easiest way to add organic matter to the soil. “Cover crops improve the soil structure by punching big holes into it with their roots. When those roots decompose, they stabilize the aggregates so those macro pores stay there a long time and can actually reverse compaction.” In comparison, tillage breaks up the macros, thus shredding all the organic matter that’s connecting and holding the soil together.  

How to Choose Cover Crops  

  At the second panel on cover crops, “Digging Deeper into Cover Crops: What’s Happening in Oregon?” Gordon Jones, Assistant Professor, OSU, Southern Oregon Research & Extension Center, delved into the myriad ways to utilize cover crops in the vineyard. Before planting, Jones recommends that growers clearly define their goals. Is their intention to increase production or profitability, improve soil health or appeal to consumers looking for wines made using sustainable means? When viewed in conjunction with a given vineyard’s particular climate and soil, these goals will inform the type of cover crops that would lead to optimal results. 

  Perennial crops such as ryegrass and tall fescue have been bred for forage and high yield, and they do require frequent mowing. Legumes like fava beans, white clover and strawberry clover can add nitrogen to the soil. Be mindful when sharing the land with livestock, as Jones addressed a fungus – endophyte – that can be present in certain turf-type cover crop grasses and can be harmful to livestock if grazed. 

  From an environmental perspective, planting deep-rooted perennial crops can improve soil health and decrease runoff. These crops will sequester carbon that helps to address some climate change concerns and build soil organic matter. 

  The planting schedule for cover crops varies according to a given region. For example, in a state like Oregon, known for hot, dry summers, many cover crops are planted in the fall to establish their root system before the summer. 

  The way a field is mowed, irrigated or fertilized will result in different mixtures of species of cover crops dominating. While complex mixtures of cover crops are often planted, Jones said that generally, only a few species within a mixture contribute significantly to the cover crop’s biomass. Over seeding in alleyways can result in an improved cover crop, though one must be mindful that any existing cover crop or weeds can be quite competitive with the newly seeded plants. 

  When debating to till or not to till, Jones said that tillage could be hard on soil aggregation and the pores in the soil. “If you’re interested in maximizing infiltration and soil health, consider a notill system.”  

  He added that tillage and herbicide can be used to kill all existing plants, and they are important tools in many growers’ toolboxes. Once the soil is devoid of existing vegetation, one can more successfully establish a cover crop free from unwanted plants. Those opting to farm using organic and low-input means by not using pesticides may need to contend with other plants sprouting alongside their cover crops. Also, self-seeding or self-regenerating winter annuals planted in the fall that go to seed by May and sprout again in the following fall can afford minimal soil disturbance. 

  In conclusion, Jones pointed to preliminary research in Southern Oregon, Ithaca, New York, and South Australia that suggests actively growing cover crops directly underneath the vine can de-crease the need for under-vine herbicide or tillage. Which species of under-vine cover crop to plant in Oregon is still an open question. The ideal species would be low growing, competitive against weeds, but not too competitive with the vines. Further work needs to be done in evaluating undervine cover crop options before growers add this to their toolbox.  

Additional Resources  

  Those looking for professional guidance can hire a consultant such as Rebecca Sweet-Smith of Buzz Cover Crop Seeds and Corridor AgLand Consulting, who provides diverse and organic seed mixes for ecologically minded vineyards and farms in the Pacific Northwest. While not in-volved directly in growing grapevines, Steve Groff, founder of Holtwood, Pennsylvania’s Cover Crop Coaching and author of The Future Proof Farm: Changing Mindsets In A Changing World, can offer assistance to those looking to explore organic ways to mimic nature when growing cover crops.  

  Also, Amy Bartow with the USDA NRCS Corvallis Plant Materials Center presented an overview of the costshare programs available for cover cropping in vineyards along with examples of their projects to date. She recommended that interested parties get in touch with their local Soil and Water Conservation District to get information about specific programs available in their particular area.

By: Nan McCreary 

When John and Sandra Zahoudanis founded Demetria Estate near Los Olivos, California, in 2006, their goal was to honor John’s Greek heritage and family tradition of farming and careful stewardship of the land. To achieve that objective, they committed to farm sustainably and biodynamically, using phases of the planets and the moon to govern farming practices.  These practices, and a natural approach to winemaking, have led to highly-rated wines and a reference to Demetria Estate as “one of the hidden jewels in California.” 

  While biodynamic farming principles are not new—the Old Farmer’s Almanac has been recommending “planting by the moon” since 1792—Demetria Estate was one of the first in Santa Barbara County to embrace the concept. “Biodynamic winemaking is our passion,” the Zahoudanis’ son, Alexis, who now runs the winery, told The Grapevine Magazine.  “We are trying to put back in the earth what we’ve taken out, and we’re doing it in the most natural way possible while incorporating the lunar calendar.”   

  Demetria, named for John and Sandra Zahoudanis’ daughter, sits on 213 picturesque acres above Foxen Canyon in the Santa Ynez Valley. The altitude of the property ranges from 1,100 to 1,450 feet, making it one of the highest in the appellation. When the Zahoudanises purchased the hillside vineyard from the well-respected Andrew Murray Family, it was planted exclusively with Rhône varieties. Today, the family farms 43 hillside acres of Rhône grapes, including Viognier, Marsanne, Roussanne, Picpoul Blanc, Grenache Blanc, Cinsault, Counoise, Grenache, Syrah, and Mourvèdre, plus small plantings of Tempranillo and the Greek Assyrtiko. Demetria also produces Burgundy-style wines, sourcing organic Pinot Noir, Chardonnay, Pinot Blanc and Pinot Gris grapes from select cooler-climate vineyards in the Santa Rita Hills and Santa Maria Valley. 

  From the beginning, the Zahoudanis family has farmed sustainably and biodynamically. Their first winemaker, Michael Roth, now of Lo-Fi Wines in nearby Los Alamos, was a big proponent of natural wines, as is current winemaker Ryan Roark.  Philippe Armenier, the renowned biodynamic expert from the Rhône Valley, guides Demetria’s farming practices. They treat the vineyard as a living organism, with soil, plants and animals working together to promote health and vitality. Farming is entirely organic, meaning no chemical fertilizers, herbicides or pesticides. For example, sheep on the property eat weeds and fertilize the soil during late winter and early spring when the vines are dormant. Demetria also plants cover crops, including nitrogen-rich legumes and daikon radishes, to protect the topsoil and nourish the vines. The major pest, according to Zahoudanis, is leafhoppers, which are controlled using natural predators such as ladybugs and organic, biologically-approved pesticides, including sprays containing fermented and herbal teas. 

  From pruning to planting to harvest, vineyard tasks are determined by a biodynamic calendar, which categorizes days into four groups—flower, fruit, leaf and root—based on lunar cycles and astrological signs. Each day also coincides with one of the four elements of nature—earth, water, fire and air. Root days, for example, are when the moon travels through any of the Earth signs (Capricorn, Taurus, Virgo) and are best for planting, replanting and pruning. Fruit days are associated with the Fire constellations (Aries, Sagittarius, Leo) and are ideal for harvesting crops. For some, planting according to lunar cycles is somewhat of a mystery, but proponents consider this an attempt to harmonize with nature to maximize yields and keep the vineyard sustainable.   

  “Our consultant, [Armenier], works with our vineyard manager and vineyard foreman to care for the vines,” Zahoudanis said, “and I let the wines speak for themselves. The fruit is really gorgeous and expresses itself beautifully as a more natural product.” 

  Demetria applies the principles of biodynamics and sustainability in the cellar as well as in the vineyard. “We know our vineyard well, and we know when to pick so we don’t have to manipulate the fruit,” Zahoudanis said. “We use minimal sulfur, and we don’t add acid or tannins. We don’t want a chemical experiment going on in our winery.”   

  Demetria relies on native yeasts to start fermentation and does not inoculate for malolactic fermentation. Zahoudanis said they filter their wine simply by racking and will only apply fining if the tannins are too harsh, and then they will use bentonite, a natural product. Ultimately, he explained, the goal is to “produce wines that are complex, while being food-friendly and approachable, not just for the connoisseur, but for the everyday wine lover that lives in all of us.” 

  Demetria has achieved that goal. Its wines—and its beautiful Mediterranean-style winery with panoramic views of the vine-covered hills—have received enthusiastic reviews from critics and everyday consumers alike. Recent awards include 2016 Rosé – “Year’s Best Rosé! Wine & Spirits Magazine; 2014 “Cuvee Sandra” Pinot Noir – 94 points, Wine Enthusiast and 93 points, Wine Spectator; 2014 “North Slope” Syrah, 91 points, Wine Enthusiast; 2013 Estate Chardonnay (Santa Barbara County) – 93 points, Vinous; and 2013 “Cuvee Matia” Grenache – 91 points, Wine Advocate. 

  Even with a barrel full of awards, Demetria is not resting on its laurels. Since establishing the Demetria Estate, the family has been changing the composition of the vineyard, uprooting much of the once-predominant Syrah, and planting grapes such as Mourvèdre to produce more interesting blends. A favorite is Cuvee Constantine, a red blend styled after the famous Chateauneuf du Pape reds made from Grenache, Mourvedre, Cinsault and Syrah. Another favorite is Cuvee Papou, which includes Grenache Blanc, Marsanne and Roussanne. The name “Papou” is Greek for grandpa and honors Demetria’s founder John Zahoudanis, a grandfather who passed away in 2020. Demetria also releases a sparkling version of the Cuvee, produced at Rack & Riddle in Healdsburg, California. “We really like the sparkling wine,” Zahoudanis said, “but it’s not our forte.  It’s too time-consuming.  We might as well give our grapes to folks who know how to make it.”  

  Demetria has recently begun producing a wine from the Rhône grape Picpoul, which is gaining traction among wine aficionados all over the world. Beton Blanc (beton means “concrete white” in French) is 95% Picpoul Blanc and 5% Assyrtiko and is aged and fermented in concrete eggs. “Concrete is a neutral vessel, so you don’t get flavors like you do from oak barrels,” Zahoudanis said. “But because it’s semi-porous, you do get oxygenation, which enhances the minerality that already exists in a lot of varietals.”   

  According to Zahoudanis, wine can be made quickly in concrete eggs: the Beton Blanc is ready five months after harvest and can be bottled by February. 

  Currently, Demetria makes 6,000 to 9,000 cases of wine annually. “We can’t plant more because we’re limited by geographical constraints,” Zahoudanis said. “We sell some of our fruit, so we could scale that back and produce 10,000 cases, but generally, we’re good where we’re at(sic).”    

Zahoudanis does envision planting more.  

  Tempranillo, a grape that’s doing exceptionally well on his property. Whatever he endeavors to do, if the past is prologue, the future looks very bright for Demetria Estate. “We’re just glorified farmers,” he said. “We’re beholden to Mother Nature, and yes, winemaking requires knowledge and art, but it’s not rocket science.  If you don’t over-manipulate it, you can make very good wine.” 

To learn more about Demetria Estate, visit…www.demetriaestate.com 

By: Gerald Dlubala 

The grapevines that a grower depends on for their livelihood are vulnerable to temperature changes that can damage the buds, fruit and even the vine. One of the most unfavorable temperature conditions is frost. Most frost conditions are radiation frosts, characterized by dry, cold air masses that settle into an area with the dangerous combination of no noticeable wind or cloud cover with a low dew point. Temperatures can be relatively warm throughout the day, with the ground retaining heat. As the sun sets, the ground warmth radiates to the upper atmosphere, allowing colder air to fall and settle into the pockets of space now available at lower elevations. Proper frost protection measures can help avoid damage and make the difference between a profitable or unprofitable year. 

Shooting The Breeze And Fighting Vineyard Frost 

  “Wind machines play a major role in protecting your vineyard from the elements of frost,” said Dean Hauff, Marketing Manager for H.F. Hauff Company Inc. “It only takes about 20 minutes before frost starts to damage to your vines, and it’s absolutely critical to protect the primordia bloom. It’s the difference between successful and unsuccessful yields. The primary bloom produces the highest quality fruit, and wind machines help protect the high-quality grapes needed to make premium wine.” 

  Hauff told The Grapevine Magazine that his Chinook wind machines work independently without any other means of auxiliary heat about 90% of the time. The only time a wind machine, or any protection strategy, struggles to be effective is in the rare occurrence of an advective freeze condition. An advective freeze happens when large, arctic air masses replace the warm air and are associated with moderate to strong winds, no temperature inversion and low humidity.  

  “Warm air rises, and cold air sinks,” said Hauff. “We all know that, but at some point, the warm air stratifies in the atmosphere, creating an inversion layer that holds in the warmer air. Wind machines work by pulling the warmer, more buoyant air from that inversion layer and mixing it with the colder, denser air on the ground floor. The fan shaft of the Chinook’s top gear head is built with a six-degree angle of attack, enabling the fan to pull the warmer air from higher altitudes, estimated to be approximately 350 feet up into the atmosphere. The movement of air combined with the mixing of the warmer and cooler air raises the temperature three to five degrees Fahrenheit on average, a notable difference.” 

  H.F. Hauff’s Chinook wind machines are useful year-round in vineyards. They help protect the fruit buds in the spring, the leaf structure in fall, allowing for the continuation of Brix development in the grape berry, and they help protect the vine from excessive cold in winter. The first commercial wind machines were sold in 1937. Since then, research and development have continued to improve coverage, serviceability, performance and ease of operation.  

  “They really are a lifetime investment,” said Hauff. “Wind machines are long-lasting, require only minimal service, yet they retain a high resale value if needed. They’ve allowed vineyards to expand their crop production by transforming frost-prone areas of their farms into fully useable crop-producing areas. Using wind machines in the vineyard lessens the burden, anxiety and stress that goes along with the risky business of growing crops. And with tighter profit margins, it’s always important to produce a marketable crop every growing season.” 

  Today, wind machines are more economical and easier to maintain and service than ever before. They’re considered one of the best tools in protection against radiant frost, lessening and sometimes eliminating the need for extra heaters, smudge pots and water. Wind machines work to bring up the overall vineyard temperatures on average three to five degrees Fahrenheit above the critical temperature point, even in winter temperatures of -15 degrees Fahrenheit or less. Critical temperatures vary depending on the varietal and the stage of development of the vine. The more advanced the stage of development, the less the plant tissue will handle below the 32 degrees Fahrenheit mark. 

  “Our Chinook wind machines use propane, diesel, natural gas or electric,” said Hauff. “The propane units burn about 13 gallons of fuel per hour, and the diesel units use about five and a half gallons per hour. One Chinook wind machine effectively covers 15 acres of fruit and trees and up to 18 acres of vines or vine plantings. They can start and stop automatically and can even be controlled and monitored remotely through telemetry via your cell phone, computer or tablet, no matter your location.” 

Wind Where You Need It 

  “As to placement, we map out and locate each of our wind machines individually, either on paper or in person,” said Hauff. “Our goal is to maximize fan coverage in the vineyard without going outside of the specified boundaries. We protect the lowest ground first, as the coldest air will naturally settle there. Then, we account for natural drift and locate our wind machines 40 to 60 feet into the direction of that natural drift. We also feature special models for uniquely contoured or sloping grounds. Our Chinook fan propeller extends coverage an additional 100 to 150-foot radius beyond competing products, and the unique and exclusive trailing edge wedge of our Chinook fan propellers increases the velocity of the air and widens the sector angle of coverage from 47 to 49 degrees out to 80 degrees.” 

  Hauff said that ice nucleation begins to form after four minutes of no air movement under normal radiation frost conditions. Chinook fans start protecting the fruit bud and plant after three and a half minutes. In addition, Chinook’s more comprehensive sector angle coverage mixes air in the horizontal and vertical plane, providing additional plant tissue protection from the ground up in even, uneven or up to four degree sloped areas with no special add-on equipment needed.  

  Hauff also offers a model that raises and lowers to the ground via hydraulic cylinders to eliminate the need for climbing and allow more accessible and safer servicing and maintenance. Annual recommended preventative maintenance consists of changing oil, checking the gearboxes, and greasing the tower and fan. Hauff said that this is usually accomplished in under an hour and requires no specific skill or unique expertise.  

Grapevines In The Mist: Battling Frost With Misting Machines 

  Another method to thwart the harmful effects of frost is through a technique involving misters and targeted directional spray. Resource West, Inc. offers humidification systems to optimize and maximize operations and serve multiple purposes within many industries, including vineyards and wineries. Their thermodynamic humidification systems protect vineyards from adverse weather conditions ranging from extreme heat through frost and freezing temperatures. The units add humidity into the air when needed or provide cooling for crops during extreme heat situations. These humidification systems give vineyard managers better crop control while providing winemakers better aging control over their products. The system can be successfully used indoors in barrel and aging houses and outdoors throughout the vineyard.  

  “Our humidification systems work by 3x convective dilution (thermophoresis), velocity control for droplet trajectory and droplet size control,” said Robert Ballantyne Jr., Senior Vice President, Principal Engineer, and Atomic and Molecular Spectroscopist for Resource West Inc. “Our larger, outdoor systems offer surface tension control for proper wetting of soil or foliage to fit the current environmental conditions and offer protection from frost, damaging cold or extreme heat.” 

  Ballantyne Jr said RWI’s humidification systems get positioned in a vineyard’s higher elevations, allowing the cooling process to cascade down the slopes. “We cover large acreage, but for the best use, a civil engineering plan should be worked out to discover the best placement of the units to realize the greatest effectiveness of the systems. We determine the optimum number of units to locate within your vineyard through thorough questionnaires and detailed weather analysis.” 

  A misting humidification system allows water droplets to freeze and coat any new or green exposed plant tissue, providing a protective coat for that new tissue against frost conditions. Experts recommend providing a steady or continuous stream of droplets for maximum protection when conditions remain below freezing. 

  “In addition to frost protection, our units provide a nice cooling effect from the evaporation that naturally takes place,” said Ballantyne Jr. “Heat relief from our systems protects crops in temperatures ranging up to 120 degrees Fahrenheit. And since the cooling process is physics-based, the success rate is 100%. The decision to do it at that point is usually a cost-benefit decision, based on cost and the amount of acreage covered by the units.” 

Easy To Own, Easy To Use, And Easy To Maintain  

  Ballantyne Jr. said that many clients prefer a rent-to-own option when choosing a humidification unit. RWI always performs the analysis and engineering tasks needed before purchase, but the systems are fully functional and generate benefits on a year-round basis. The number of benefits gained by year-round use varies based on the client’s geographic location.  

  “Maintenance and training are non-factors in choosing our systems for your vineyard,” said Ballantyne Jr. “We recommend that our units get an annual power washing, and the training involves understanding your vineyard’s elevation changes and how cooled air will flow and sink with varying increases in density. With RWI’s systems, you gain a partner in crop protection and enhanced product quality. If you are a client, we work with you to continuously improve performance and maximize your return on investment. We are proud to offer the most efficient systems on the market, and our engineering staff is always available to help ensure the highest return for our clients.” 

  Inside the winery, where humidity is also critical, RWI’s humidification systems aid in controlling the barrel aging process, giving winemakers better control of the quality of their final product. Benefits of increased control are more effective management of angel share losses, improved barrel loss conditions, and enhanced quality and consistency of wine, ultimately leading to better financial performance. 

Like a Warm Hug: Wrapping Vines as Protection from Cold  

  Can something as simple as wrapping your vines in a cover protect them from frost? Two estates in the Anjou-Saumur region of France have participated in frost protection trials, using a common backyard tactic for protecting tender vegetation. Monitored by the National Institute for origin and quality, grapevines were wrapped in a P30 type winter cover to determine if it protected the vines in frost conditions. Complete frost protection was reported in the 2020 growing season. In 2021, Mother Nature provided even more opportunities to test the process as recorded temperatures dropped below freezing several times over four weeks. Again, the results were very positive, as the wraps reduced frost damage significantly. Unprotected vines suffered nearly a 90% loss, whereas protected vines experienced only a 10% loss. Another grower used a double layer of fleece as their wrap of choice and again showed success, recording up to a four-degree difference in the covered vs. uncovered areas.  

  However, the Institute warns that although it looks promising, more research is needed to understand the full scope of how wrapping affects the grapevines, not only externally but also within the vines’ structure, before they issue a recommendation on the future viability for this type of protection on a widespread basis. 

By: Gerald Dlubala 

Temperature control and consistency are magic words to a winemaker. From planting through harvest, packaging and storage, the winemaking process is vulnerable to temperature instability or fluctuation. With each growing season bringing the potential for unique challenges regarding those temperature fluctuations, the winemaker must be prepared to react to situations as they occur and protect their product under all conditions.  

  Providing stable and consistent temperatures and humidity levels brings that protection and allows the wine to retain freshness, flavor and predictability. For bottled wines, humidity fluctuations can cause problems, including shrinking corks, mold and contamination.  

  The ideal temperature for storing grapevines to inhibit active growth yet keep the stock viable until conditions are suitable for planting is between 34 to 36 degrees Fahrenheit (1-2 C). After harvest, when bringing the grapes in for processing, it’s unknown what the current weather and ambient temperatures will be until they are upon you. If too warm, best practices advise a cool-down period before pressing, after pressing, or both, depending on the variety and type of fermentation used. If that’s not possible, it may be advisable to store grapes in a temperature-controlled facility until ready for processing. 

Refrigeration Capabilities are Necessary for Quality Wine Production 

  Carolyn A. Warnebold is the majority owner of OakGlenn Winery, located in historic Hermann, Missouri. OakGlenn Winery produces about 400 gallons of their popular Norton variety from an original vine stock planted in 1859. Other wines offered onsite are grown and processed at separate locations. 

  “There is no doubt that without a good refrigeration system, you’re not going to achieve good wine,” said Warnebold. “Our grapes go through crush immediately after harvesting and are then placed in fermentation tanks for 24 hours before adding the fermentation ingredients. During fermentation, the must has to remain at 70 F. Our chilling equipment runs a glycol and water solution at 65 F through jacketed tanks to control the cold fermentation of the must.  

  After a 10-to-14-day fermentation, we press, tank and hold the juice and grapes at 65 F until the fermentation and settling process is complete. The juice/wine is then racked after two months, placed in another tank where the wine rests at 32 F. Two weeks before bottling our wines, we drop the temperature to 22 F to drop any further tartrates. Our wine is then filtered immediately before the bottling process and is usually ready after six months.  

  We process our white wines and blends similarly, except for the fermentation, which is done with juice only. We do not perform any further barrel aging of our wines. We hold our bottled wines in our tasting and sales rooms at a consistent 45 F.” 

  All of the tanks at OakGlenn Winery use the same glycol and water chilling system to control temperatures and guarantee consistency, including their cased wine warehouse. According to Warnebold, glycol chillers are much more cost-effective than other types of systems on the market. 

Cold Storage Essential to the  Flow of Quality Winemaking  

  Chris Graves is the winemaker at Naumes Family Vineyards, operating Naumes Crush and Fermentation LLC as an outsourcing option for wineries. He told The Grapevine Magazine that cold storage capability is an essential tool for the winemaker, not only for proper fermentation but also for allowing a winemaker to buy time and provide improved processing and cold soaks.  

  Additionally, if a winery uses large tanks, chillers are essential in controlling overheating and any corresponding sticking issues in the tank. When fermenting rosés or lighter wines, longer fermentation times are needed to develop the aromatics, so temperature control is even more critical. 

  “While grapes are still on the vine, they are naturally protected from microbes like bacteria and yeast,” said Graves. “But once harvested, that natural protection is compromised, and exposure begins. 

  When the vineyard is at its busiest time of year, meaning harvest, getting those freshly picked grapes delivered to the winery for processing and into the fermentation vessel within an acceptable temperature range can be tricky.  Additionally, grape varieties’ sugar levels and freezing points differ after harvest, so it’s important to control and maintain proper temperatures as conditions change. If that’s not possible, then offsite cold storage options become a winemaker’s best friend.  

  Grapes handle the sorting and destemming process better when cold and dense, especially in quality reds that demand more fruitiness and less tannin extraction. Most often in red winemaking, the winemaker will want to keep the must in fermentation vat cold for a cold soak before fermentation.” 

  That’s where facilities like Naumes Crush and Fermentation can help the vineyards produce quality wine, offering cold storage options and space for wineries to store their grapes at the preferred 33 F directly after harvest.  

  “It can be anything that causes a need for cold storage that some smaller craft wineries just don’t have,” said Graves. “It might be a weather event that causes a mass fruit pick from the vines, something unplanned that changes a vineyard’s scheduled harvest plans or even complications with vineyard equipment that causes harvest issues and throws off schedules and deadlines. Wineries can buy time if they need to pick grapes but aren’t ready to process just yet. Plus, with the time to plan the process, information flows better, making the process more accurate and consistent with higher quality and better results. It’s just easier to have and stay on schedule. Utilizing offsite cold storage like ours assures a winemaker that their product is held and processed correctly, if needed,  by knowledgeable and experienced staff and winemakers. It ultimately results in higher quality wines and better, more efficient logistical flow.” 

  Most wineries use standard glycol chillers because of the benefits that come with them. First, they put less stress on pumping equipment because the glycol mixture has built-in lubricating properties.  

  Second, glycol chillers have a lower freezing point, allowing lower operating temperatures without concern over system freezing and damaging the unit.  

  Finally, since glycol chillers allow better holding temperatures, they help minimize heat pickup on delivery and return. Heat pickup tends to be more of an issue in higher volume production facilities that use more piping in their production. 

  Smaller operations can use mobile heating and cooling units. They offer the convenience of portability to use when and where needed, but that convenience generally means limited capability compared to a more extensive plumbed system.  

  Graves recommends a plumbed system when a winery reaches the one to two thousand cases produced rate, if nothing else, because of the benefits of a more extensive, built-in system. For example, a plumbed system allows a wider variety of wine to be produced onsite because of the availability of the unit to provide heating and cooling, essential in remaining consistent in critical times of fermentation and wine storage.  

  “The best recommendation I can give someone looking at refrigeration and cold storage is to use a plumbed and closed glycol system, and make sure to buy one that is oversized for your current production needs,” said Graves. “I see a lot of wineries that purchase and install a system to fit their immediate needs, and then when they start to increase production or grape/wine variety or have a great production year, that system is already undersized for their needs.”  

  One of the biggest issues we see in wineries just starting out or in the small established craft wineries. If you have any thoughts or desires to increase production, move into new varietals or even do something different in the future, purchase and install a refrigeration or cold storage system that is oversized in the beginning so that you can grow into it seamlessly as a winemaker.  

  Get a quality plumbed system that also uses quality pipes and fittings to handle extreme temperatures and varying pressures that occur in winemaking.” 

  Graves also recommends that winemakers use quality temperature controllers, like TankNet, and match them with reliable software systems that connect with a cloud-based network, allowing the controllers to be accessed and used with smartphones or other remote-control devices to instantly address any problems or concerns and help maintain process consistency and integrity.  

  “You know, consistency is everything, and consistent temperature control is the key to producing a bottle of quality wine. Wines don’t tolerate fluctuating temperatures, so if you can do it yourself, do it, but if for any reason you can’t, it’s worth it to have an offsite company handle your storage, crush and fermentation needs. Naumes offers the full spectrum of post-harvest services, from grape to bottle, including lab work, analysis and more.  

Recommended Temperature Guidelines 

  Temperature fluctuations can have a detrimental effect on bottled wines, which react to heat by aging faster. In addition, direct sunlight or artificial light can react with phenolic compounds in the wine and cause spoilage. Lighter-colored wines are more susceptible and therefore more apt to be packaged in tinted bottles. 

  Wines undergoing malolactic fermentation are generally held at 68 to 75 F (20-24 C). Barrel storage rooms require constant temps around 55 to 60 F (13-16 C). Clarification processes like fining, centrifuging and filtering needs temperatures in the range of 32 to 77 F (0-25 C).  Hold sparkling wine at temperatures below 54 F (12 C) to promote the required carbonation, and when bottling wine, temperature recommendations are typically around 60 F (15 C) to discourage or limit dissolved oxygen during the filling process. 

  Optimal wine storage has traditionally been listed at 55 F (13 C), but according to winemakers, red varietals can safely be stored between 53 to 66 F (12-19 C). You can go a little cooler with champagnes because of their needs–50 to 59 F (10-15 C). Wine should never be frozen or stored for a length of time above 68 F (20 C). 

By: Cheryl Gray   

Inside every grape is the flavor upon which crush season depends. Capturing that flavor is a skill that every vineyard around the world strives to master. 

  From traditional methods to the latest technology, wineries have a singular goal in mind: extracting the very best from a grape crop nurtured during the past year. 

  The Pellenc Group is a global manufacturer of equipment and tools used in viticulture. Its subsidiary in the United States, Pellenc America, is headquartered in Santa Rosa, California. The company’s technologically advanced products make it a leader in the industry and help wineries get the most from their grape crops. 

  One of Pellenc’s innovations is Smart Glass, a connected sensor used to transfer wine, automatically shutting off when complete. The Smart Glass receives information either from a remote control or Pellenc’s pump pilot module and alerts the operator whenever there is a change in the liquid. Applications include not only liquid transfer but also blending, cold settling and gas detection. Smart Glass touts cost-effectiveness in that it improves productivity by facilitating automated transfers, freeing up workers to do other tasks. It also promotes reduced water consumption and wine loss. The product’s year-round multiple applications, including water flushing and flotations, also help save time and money. 

  Another time-saving product from Pellenc is Smart Oak, is an automated tool with a user-friendly interface. Instead of the weeks it normally takes to complete oaking, Smart Oak is designed to reduce that to just a few days. The system includes a soaking vat, pump and built-in sensors, the latter of which manages the speed, control and successful repetition of the entire oaking process. Smart Oak allows wineries to use wood chips, staves and blocks to achieve the finished wine product. It also eliminates the need to purchase and store barrels. 

  Pellenc’s Flash Détente is a two-step thermodynamic process that reduces fermentation time from two weeks to three days and increases yield by 3 to 4%. The first step heats grapes, juice, wine or lees to 170 F, allowing wineries to eliminate pyrazine and any green pepper taste while achieving enhanced color extraction. The grapes are then pushed into a vacuum chamber, where the water inside the fruit quickly turns to steam, instantly blasting the skin, which releases tannins and anthocyanins.  

  Finally, the Pellenc Smoke Taint Mitigation protocol is a combination of Flash Détente operations and enzymatic macerations. Combining the two gives wineries the ability to treat tainted berries before fermentation without stripping the finished wines of their character and flavors. 

Facing Challenges 

  While new technology is helping wineries reduce costs and maximize crop yields for crush season, the deadly coronavirus and lingering drought continue to be tough challenges even for the most experienced winemakers. 

  Just ask Penelope Gadd-Coster, the award-winning winemaking consultant for Rack and Riddle Custom Wine Services in Sonoma County, California. She said that many of the safety steps Rack and Riddle put in place last year to protect against COVID-19 remain. 

  “Well, just when we thought we might be over masks, they are back! Many things will be similar to last year: masks indoors, visitors will need to be masked, still need an appointment for meetings, Zoom will still reign as the communication tool.” 

  These are just a few of the strategies that Rack & Riddle has deployed to operate safely during the pandemic. With the tonnage of grapes it processes each year, the company has incorporated technology to accommodate some of its workloads.  

  “Rack & Riddle has invested in some automation that is allowing us to keep steady staffing. For example, tirage bins are filled by robots. This was a task that was done by seasonal workers in the past,” said Gadd-Coster. 

  As for the drought plaguing California and elsewhere, Gadd-Coster told The Grapevine Magazine that growers are being forced to take drastic measures to conserve water for this year’s crush season. 

  “The drought is a bigger change as Healdsburg is having to drop [usage] by 40%. Businesses are having to come up with ways to make this happen as well. For the vineyards, [it’s] either recycled water or no water for vines unless the growers filled reservoirs before the restrictions. Many thought that harvest would be early due to the drought, but it is actually coming later than average in many areas.” 

  Other grape-growing regions, including the Pacific Northwest, have also suffered from extreme heat. Richard Hoff, Director of Viticulture for the renowned Mercer Ranches in Washington State’s Yakima Valley, said that the high temperatures have impacted their crush season schedule.  

  “As far as harvest impacts, due to the 110 F, 115 F  heatwave we had, grapes are ripening quickly, and we expect a somewhat early harvest.” 

  Gadd-Coster added that supplies and equipment are harder to come by as the businesses that provide them are tackling some of the same obstacles as their vineyard and winery clients. 

  “Equipment and supplies are taking longer. That still hasn’t changed much yet. And some things are just not available–long wait times. This was the case with some of our winemaking additives, some packaging items.” 

  John Derrick is Vice President of Vineyards for Mercer Ranches. He says there has been significant lag time for other pieces that are critical to a successful crush season. 

  “The supply chain for parts is just as bad for grape equipment and supplies. Finding and hiring new employees is definitely a big struggle this year. We are lucky in that we utilize H2A and do not foresee any people issues at this time.” 

  The H2A program allows American companies that meet strict regulatory requirements to bring foreign nationals to the U.S. to fill temporary agricultural jobs. Many crush seasons depend upon these workers. However, some wineries are increasingly looking to technology to replace manual labor for specific tasks. 

  Sorting fruit is one of those jobs where technology can step in to help maximize results. John Felice, Vineyard & Winery Equipment & Product Specialist for Pellenc, points to the manufacturer’s Vision Optical Sorter as a solution.  

  “The Vision-2 features the best optical eye in the industry combined with the best software to produce the highest level of quality consistently throughout the harvest. The cleated belt holds the fruit from moving around and allows the Vision-2’s optical system to determine what it keeps and what it rejects. You can set the Vision-2 to keep or remove raisins and remove fruit that does not meet a certain size or color level. With today’s labor shortage, the Vision-2 will control up to six other machines on the receiving and sorting line. This level of automation allows you to run the optical line with one to two people.”  

Developing a Crush Pad 

  Equipment and supplies for crush pads are critical components for a successful crush season.  Experts say that coordinating with knowledgeable companies makes a big difference for wineries developing a crush pad. 

  The Vinter’s Vault helps wineries of all sizes solve the dilemma of exactly how to execute a crush pad. With two locations in Paso Robles and Temecula, California, and a third in Texas, the company’s reach is global, including clients located throughout the U.S. and in Mexico, Canada, Costa Rica, China, Nova Scotia and Indonesia. The Vinter’s Vault works with several manufacturers to provide wineries with equipment such as destemmers, presses, tanks, lift conveyors, sorting and vibrating tables. Ryan Horn is the company’s President. 

  “We do full crush pad set-ups and often help clients with their designs. We commonly do full design layouts for new and expanding wineries where we can design and plot the flow of work for their view and to fit their needs, desires and location,” said Horn. “For crush pad equipment, we are most known for the Athena Presses, which are very state-of-the-art central membrane presses that are faster, more gentle and more efficient than any press on the market. Our IMMA crush pad equipment is also well known.” 

  Pellenc also deploys a design and sales team to work with wineries worldwide to develop crush pads, including wineries in California, Texas, the eastern United States, France, Italy, Germany, Spain, Canada, New Zealand, Australia, Argentina and South Africa. Felice said that Pellenc is there from beginning to end.  

  “Pellenc design engineers and salespeople will work with the winery team to gather the necessary information and put a proposal together with CAD drawings to meet the demands      of the winery with throughput and efficiency in mind.” 

  Companies that provide equipment and supplies for crush season agree that there is no cookie-cutter approach to servicing their vineyard and winery clients. Among other things, 24/7 service and technical support are high on the list of reputable firms. Experts say those are the companies that understand that fruit won’t wait.