The Water and Your Wine


Galileo once said “Wine is water, held together by sunlight.” With all the record rainfall that NY has been getting this year, it’s been impossible not to think about how water affects wine quality.  Too much or too little can significantly impact the way a harvest will develop.  Since the largest chemical component of wine is also water, Galileo was not that far off in his estimation.
Nearly all of the main physiological functions of the vine depend on water for healthy growth.  During transpiration, which is the breathing mechanism of the vine, water is pulled from the soil by the roots, transported it up the plant through the part of the vascular system (think of it like the blood vessels of a plant) called Xylem, and it is released out through the stomata, which are openings on the undersides of the vine leaves.  If one thinks of water as being pulled up through the vine and out the leaves by the air, then one then has the concept of transpiration.  This evaporative pull allows the vine to continue pulling water and essential nutrients from the soil for all its main functions.  

The effects of water in the vineyard rely specifically on what time of the growing season the surplus or shortage of water occurs.  At bud break, the vines have been pruned and are ready to begin a new vintage.  At this time, it is important that the vine have enough moisture in the soil to begin the production of leaves and shoots which will soon become large enough to begin the process of transpiration and photosynthesis.  During bloom and fruit set, it is still important for the vine to have adequate water supplies from the soil; however, rain can be problematic because it interferes with the pollination of the grape flowers.  While domesticated grapevines do self-pollinate it is important that the calyptera (the tiny cap covering the stamen and pistil of the grape flowers) release and fall off without sticking due to moisture to ensure effective pollination. Rain can inhibit this process and lead to a lower set and higher incidence of shot berries.

Once the berries have set, the next stage of the growing season is the cell division phase during which the grape produces all the cells that will be present in the final berry.  This is a critical time to monitor water for the vine grower.  Too little water will inhibit the process resulting in fruit that is far more likely to split from too much water later in the season.  Conversely, too much water at this point can bring disease pressure from mildews.  If not carefully controlled, these mildews can cause damage to the leaves and skins of the grapes which will impact photosynthesis and later impact the color and flavor development of the fruit.  

Next comes cell expansion, when the berries get bigger, and veraison, when the berries change color and soften.  At this point, it is important to monitor water levels since too much water will burst the rapidly expanding fruit and too little water can be used to control berry size.  This is a time where the quality of the final wine is a determining factor since too much or too little water may impact flavor concentration.  This point also carries the danger of having too little water for the vine to function properly.  This issue can lead to the vine halting photosynthesis, think sugar accumulation, and in turn, the ripening process.  If this state continues unchecked, it can mean the loss of the crop or the loss of the entire vine due to water stress.  Vines will begin to drop leaves under extreme water stress which will impact the ability to produce sugars even if water returns within the next few days.  Sunburn can also present a problem once the leaves shut down as they curl up away from the sun and can expose the fruit skins to direct sunlight in hot weather.  

Harvest is the last critical point in the growing season.  Too much water during this time can dilute the flavors, sugar, and acids of the fruit leading to a less concentrated wine in the winery.  On the other hand, too little water at harvest carries the risk of the grapes beginning to desiccate which causes the sugar to rise rapidly and without warning.  Winemakers must quickly decide how much is too much or too little and harvest the fruit before the desired qualities are lost.  

It is a delicate balance that wine growers have to walk between too little and too much water.  In areas which use irrigation, this is less of a concern because water can be applied as needed.  However, in areas which irrigation is not allowed or in vineyards which do not have irrigation one is at the mercy of Mother Nature since water plays such a vital role in the development of wine grapes.

Nova Cadamatre is the first female winemaker in the US to achieve the title of Master of Wine and one of only four American winemakers to do so. Currently she resides in the beautiful Finger Lakes of upstate NY with her husband, Brian, and son, Nathaniel. By day she is Director of Winemaking for Canandaigua Winery for whom she makes the 240 Days wines; a Riesling, dry Rose, and Cabernet Franc. By night, she is the owner of Trestle Thirty One, a high end boutique wine brand making age worthy dry Riesling. In 2014, Cadamatre was named to Wine Enthusiast’s Top 40 under 40 list and has numerous 90+ scoring wines to her credit. Originally from Greer, South Carolina, Cadamatre began her career in wine after moving to New York to pursue horticulture. As one of the first graduates of Cornell’s Viticulture and Enology program in 2006, Nova relocated to California to assume a number of winemaking roles with many iconic wineries including Beringer, Chateau St. Jean, Chateau Souverain, and most recently at Robert Mondavi Winery. There she was the red winemaker focusing on Cabernet Sauvignon from the iconic To Kalon Vineyard. Nova is a WSET Alumni, blogger, wine writer, Ningxia Winemaker Challenge contestant, and is active on social media. Follow her on her blog at, on Twitter @NovaCadamatre, on Instagram @nova_cadamatre, and follow her wine brand at

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