Life Cycle of the vine in Summer
SUMMERTIME IN THE VINEYARD (for RERSERVEBAR)
HOLLY SHAW, DIPWSET, RESERVEBAR WINE CONTRIBUTOR
DEVELOPING THE GRAPES
A Napa Valley vineyard in the middle of summer is a stunning experience. When standing on the valley floor, you can feel the heat radiating from the earth. The smell of a sweet mix of lavender, brush, and green grasses waft in the gentle breeze. The bees are hard at work and their vibration harmonizes with the bird’s melody. Vines are neatly lined up in satisfying rows with grapes and leaves signaling the growing fruit. Grapes on the vine receive heat and sun, an important contribution to the wine that results from the fruit. The cool breeze and temperature drop at night are just as important as it allows the grape to ripen without stripping the acidity. As beautiful as these summer days are together, this harmony creates the wine in your glass.
Every vine has basic needs to grow. The vines need to be pollinated. They need the sun’s warmth, water, and time to ripen, which is hopefully not hindered by excessive heat or cold weather. All vineyards will have various challenges that are unique to the environment adding to the complexity of making wine. Bordeaux worries about cold snaps at night, while Cabernet Sauvignon vintners worry it won’t be able to ripen fully and Merlot worries about rushing to over-ripeness in a heat spike. Napa will worry about drought, which can ultimately lead to the death of the vines, or fires that can destroy a vineyard or give unwanted flavors to a wine.
No matter where the grapes are grown — winemakers are the unsung heroes. The winemaker and grower have intimate relationships with their vines and make decisions based on both deep and long-studied knowledge and intuition. Every year is different and brings on new challenges, which the winemaker addresses accordingly. In the summer months, winemakers, growers, and vineyard owners will keep a sharp eye on water, heat, or react to unexpected enemies such as fire. I asked my friend, Mike Farmer, from Euclid Wines (former winemaker at Opus One) in Napa, CA, what he looks for specifically in the summer months.
"In summer, I walk the vineyards and look to see rainfall levels and any concern for drought. In drought times, we limit competition with grass and weed growth between vines. In seasons with significant rainfall, we will till the vegetation between the vines later. For mountain vineyard wines, we don't worry about the vegetation because there is less. We have been seeing cold nights at the moment and that is a concern in the May months. We usually see a heat spell during the later part of the season, which is the main issue for fruit ripening and hangtime on the vine."
RIPENING THE WINE
The most obvious symbol of a summer vineyard is the vine. The trunk, cane, shoots, and foliage are an important part of the vine, as well as the below-ground root system which plays a vital role in water uptake and sustaining the vine. In the earlier part of the summer, pollination will lead to the flowering of the vines. A warm, early, and quick pollination will result in an even crop. If there is rain, cold, and dampness, it can lead to a delay in flowering and will result in lower yield and uneven ripening. This can result in conditions called Millerandage or coulure, which are conditions that will affect the final grape. “Fruit set” is an important time and a term that you will hear tossed around if you hang around a vineyard long enough. Fruit set is when the flowers form a berry, and from this point, the vine will need six to eight weeks to ripen.
As summer gets underway, a vine needs sun and warmth. If the temperatures drop significantly, it can become too cold for the vine to grow. Some grape varietals need more heat than others. A Grenache or Cabernet Sauvignon will need more heat and sun than a Riesling. Heat can come directly from the sun or, in regions like Chateauneuf du Pape, the soil or rocky surfaces that reflect the sun. Light brings photosynthesis which all vines need to survive. Since July and August tend to be the hottest months in the vineyard, there are hazards that winemakers and growers will watch for. In a Napa vineyard, heat during the day results in ripeness and sugar development while nighttime temperatures drop slightly, which helps retain acidity and freshness in the grape.
BALANCING NATURE WITH NURTURE
Too much sun or too little sun can quickly become an issue. Canopy management, which is a way for growers to manage the vine, is important as the leaves grow. A grower can decide to crop the foliage down for more access to sunlight or keep leaf growth for more shading. Elevation and directional planting are other ways to capitalize on sun exposures where needed. Part of harvesting a successful crop is purely trusting nature to do what is expected, but an equal — or perhaps greater — share of the craft is making countless decisions and predictions.
As essential as sun and temperature are to vineyard growth, water is equally essential. Too much rain, or the opposite, drought, will lead to issues in the vineyard. Hail can also be a major issue in places like Burgundy and can destroy berries and crops in a matter of seconds. Vines access water through their roots through a process called transpiration, where water is drawn up through the leaves. As it gets warmer, water evaporates from the vine leaves at a faster rate, and the vine will need to take up water from the soil to compensate. Irrigation has made it possible for dry, arid parts of the world to keep vines hydrated, but the drought is still a serious issue. When a vine lacks water, photosynthesis will stop, the leaves will wilt, and the grapes will fail to ripen. If this goes too far — it will kill the vine not only for the season but permanently.
Beyond light and water, winemakers must keep a careful eye on other things that may be happening in the vineyard. Growers and winemakers will be watching for diseases that affect the roots, leaves, and grapes, along with various pests and bugs. This will all play into how the vineyard is managed. Without going into a dissertation about chemicals and spraying of vineyards, there are lots of options for vineyard owners to use. All chemicals (fungicides, herbicides, and pesticides) are tested rigorously before being used. Along with that, most quality-focused vineyards are chemically conscious and typically use non-chemical sprays and take a more natural approach, known as biodynamic farming. Unfortunately, there are things like Phylloxera, a deadly vine disease caused by an aphid that is a major issue, most currently in Oregon and parts of California, and cannot be cured. The vine will be pulled up and replanted with a more resistant rootstock.
It can be hard for a vineyard manager to relax during the summer with so many what-if scenarios, but a summer vineyard is beautiful, especially when véraison takes place. Véraison is the point when the grape begins to ripen, going from a hard pea-type texture to a softer and riper grape. Black grapes will turn red and purple, and the white varieties will become transparent. As the heat rises, the growth of the vine will slow down. The grapes will swell and fill with water, grape sugars will rise and the acid in the grape will drop.
A long growing season is important in areas such as Burgundy, Willamette, and Barolo. If you have too many heat spikes, the grapes will ripen too quickly, leading to overripe and eventually flabby or higher alcohol wine. When heat is consistent with both warmth and light, it leads to perfectly ripened grapes.
The timing of harvest will vary for every region, ranging from July thru September. Napa is famous for having a longer “hang time” which means a later harvest, while some grape varietals are early ripeners (i.e., Pinot Noir, Chardonnay, Merlot) and dictate an earlier picking. A longer hang time produces a bigger, bolder style of wine because the longer time leads to a greater concentration in the wine. I’ll dig into the harvest for fall; stay tuned for the second installment in this series! For now, I encourage you to find a vineyard to tour and stroll and taste this summer.
Amanda Barnes recently published a beautiful and expansive book, The South America Wine Guide. I asked her what she anticipates on a vineyard in the summer months. “Summer is a really exciting time in the vineyards as the wines are full of life,” says Barnes. “It’s vibrant green and the grape bunches are appearing and growing. Véraison is such a colorful moment too, and then begins the anxious wait for harvest —hoping there won’t be any hail storms and that it will be a couple of months of good, steady weather.”
It’s easy to get lost in the beauty of the vines. While standing in the vineyard looking out at the horizon of perfectly ordered rows, it is hard to grasp the depth of decision-making and hard work that goes into what's in front of you. There are so many stylistic differences spanning the globe when it comes to approach or management, but the one thing that remains the same is that no matter what mother nature orders at the vineyard, a wine will result from the fruit on the vine. If you get a chance to visit a winery during the summer months, I encourage you to relax, take a sip of wine, and think about all the work that went into producing what’s in your glass!