A Chardonnay wine tasting and evaluation workshop for winemakers was held on August 18, 2021, at the William Heritage Winery, located in Gloucester County. Chardonnay is one of the most suitable Vitis vinifera varieties for New Jersey for both north and south New Jersey. It is also one of the best white varieties for New Jersey in terms of consistency in ripening. It can be easily adapted in the winery for Sparkling, dry still varietals, and white wine blends. For example, a few wineries blended 75-80% Chardonnay with the remaining comprised of Pinot Noir, Pinot Gris, and Sauvignon Blanc. The responses to a survey weeks before the event formed the basis of discussion at the workshop. Winemakers also described how they accomplished each of their wines.
Clones: Most of the growers have Dijon clones, such as Clone 95 and Clone 96 which are cold tolerant, have known tolerance to crown gall, and produce smaller clusters (for more information read previous blog http://njvines.rutgers.edu/chardonnay-winegrape-clones-for-cool-climates/).
Harvest Parameters and Yield: Wineries monitored the sugar and acid levels to decide on harvesting. Though Chardonnay clusters hang well, some wineries picked fruits earlier because of bird attacks. In Chardonnay, yields as high as 4 tons per acre can easily be achieved with high wine quality, depending on the site’s vigor and cultural practices. However, most growers limited their yield to 2.2 to 3.3 tons per acre. Most vineyards picked their Chardonnay when sugar concentrations were in the range of 18.6 – 21.5 °Brix; Titratable Acidity 4.8-7.7 mg/L; and pH was in the range of 3.19 – 3.57. One winery picked grapes at 18.6 Brix and chaptalized by adding sugar to boost them up to 25 °Brix. One winery noted the problem of high acids which was correlated with higher potassium in the must, which they reduced by regular leaf petiole analysis and managing the potassium levels. This is one of the examples of how viticulture practices can have a huge impact on wine quality.
Cold Soaking the berry before fermentation is not common among NJ wineries. Cold soaking is done before fermentation to extract more color and flavor from the must before fermentation. This process however can be risky if volatile acid (VAs) producing bacteria are active but not checked.
Fermentation: When it comes to fermentation, most winemakers like to use a variety of yeast strains such as Levine Rhone 4600, CSM, T306, L226, CX 9, Q5, FX10, and D254 and their combinations. A comparison of notes with 2015 Chardonnay wine tasting notes indicates that wineries continue to test different types of yeasts, as their wine-making styles and understating evolve. Winemakers prefer yeasts for their specific traits. For example, one winery has always used DV 10 as a workhorse as it produces apple and Bartlett pear flavor; another winery used the combination of native yeast along with CSM and D254, and another winery used the combination of Q5 and L2226. The Q5 yeast is known for enhancing the expression of primary as well as secondary aromas. One winery used Mosaic yeast, an all-purpose strain that works for white as well as red wine and is known for creating a better environment for barrel fermentation, however, this strain is not cold tolerant and can partially degrade malic acid. Another winery used specific strains for four different clones of Chardonnay and then blended them for their 2020 Reserve Chardonnay. Most wineries performed fermentation for 10-14 days with temperatures in the range of 68°F-80°F.
Many wineries used Malolactic fermentation (MLF) and few avoided it. During MLF, tart malic acid is converted into the less acidic lactic acid by the action of the bacteria. Most used the VP41 strain of bacteria, while others used Lectoenos 450 PreAc which can be used in white and red wines, has high resistance to ethanol, and is known to produce very high MLF activity. One winery co-inoculated with Lavlin-31, just three days after adding yeast. Lavlin-31 is suited for reliable MLF under cold temperatures. However, one winery used a native strain to perform MLF. Few performed partial MLF, where only 50% of the wine went through MLF.
Containers: One winery has successfully used open-top fermentation, where the temperature ranged from 50°F -80°F. The open-top fermentation during the early stage allows exposure to plenty of oxygen contact which helps yeast build strong populations and prevents overheating and the stuck fermentation associated with it. For chardonnay, starting in steel and finishing in the barrel is the common practice. Few wineries are using cement tanks (for up to seven months) to avoid high temperatures of fermentation. Cement is a slightly porous material with countless tiny holes, that allow air to permeate through these holes and allow moderate interaction with oxygen which enhances mouthfeel. “Specific chemicals have to be used to clean it or it may crack” suggested a winery that has been using cement containers.
Wine filtration: Several winemakers used sterile filtering, often referred to when a filter size of 0.45 µm or less is used. Sterile filtering sometimes results in flavor stripping, and one must be careful when doing so. Nonfiltered wine is known to have more flavor than filtered wine, but winemakers prefer security to make sure the product is safe; hence filtration is a common practice. Residual sugars (glucose and fructose) and malic acids are classic food sources for bacteria and yeasts and hence the significance of sterile filtering. Some use rough/pad filtration that filters most bacteria and yeast but not all.
Oak Flavoring: The choice of Oak varied greatly among wineries, mostly using French Oak and American Oak. One winery used a combination of Hungarian and French Oak, where more aggressive Hungarian oak during the first year gave a nutty character, followed by the French Oak. A few wineries did not want strong oak flavors in their wines and hence throughout used neutral oak. The duration of oak varied from 10 months to 24 months, however, most had at least 18 months of aging with oak.
The program concluded with a tasting of a premium Burgundy chardonnay, which Gary Pavlis explained, was “pressed directly into the barrel, made using native yeast, natural MLF, no fining, no filtering, and with 25% new oak”.
Participating wineries: William Heritage winery (host), Auburn Road vineyards, Crosswick Creek Estate vineyard, Sharrott winery, Cape May Winery, White Horse Winery, Hawk Haven Winery.
References
Coia L. and Ward D. 2018. Wine Grape Varieties of New Jersey. Rutgers New Jersey Agriculture Experiment Station.
Jackson R. 2014. Wine Science: Principles and Applications. Fourth Ed. Elsevier.
Previous Notes on
2020 Cabernet Franc Wine Tasting and Evaluations: https://go.rutgers.edu/nljulicx
2015 Chardonnay Wine Tasting and Evaluations: https://go.rutgers.edu/6zra77ru
