First article in the series–The Seasons of Winemaking.
Spring is a crucial season for winemaking, as it marks the beginning of the annual growth cycle of the grapevines. During this time, the vines awaken from their winter dormancy and start to produce new shoots, leaves, and flowers. The viticulturists and winemakers have to monitor and manage the vineyard carefully to ensure the health and quality of the grapes that will be harvested in the fall.
Bud Break
Bud break is the first visible sign of growth in the vineyard, usually occurring in March or April in the Northern Hemisphere, and September or October in the Southern Hemisphere. It happens when the buds on the dormant canes swell and burst, revealing tiny green shoots that will eventually become branches. Bud break is influenced by several factors, such as the grape variety, the climate, the soil, and the pruning method. Some varieties, such as Chardonnay and Pinot Noir, tend to bud earlier than others, such as Cabernet Sauvignon and Syrah. This means that they are more susceptible to frost damage, which can kill the young shoots and reduce the yield.
To prevent frost damage, viticulturists may use various techniques, such as heaters, wind machines, sprinklers, or helicopters, to circulate warm air or water around the vines. They may also delay pruning until late winter or early spring, to avoid stimulating early bud break. Pruning is an essential task that involves cutting off excess or unwanted wood from the previous year, to shape the vine and control its vigor. Pruning also determines the number and position of the buds that will produce the grapes, and thus affects the quantity and quality of the harvest.
Bud break is celebrated in different ways around the world, often with religious or spiritual ceremonies. For example, in Burgundy, France, the monks of the Clos de Vougeot monastery used to bless the vines and pray for a good harvest on the day of bud break. In Chile, the Fiesta de la Vendimia (Harvest Festival) begins with a mass and a blessing of the first must (grape juice) by the local priest. In Napa Valley, California, some wineries host bud break parties and tastings for their club members and guests.
Shoot Growth
After bud break, the shoots grow rapidly, reaching up to a meter in length by the end of spring. They develop leaves, tendrils, and lateral branches, forming the canopy of the vine. The leaves are the main source of energy for the vine, as they capture sunlight and perform photosynthesis, converting carbon dioxide and water into sugars and oxygen. The sugars are stored in the roots, trunk, and canes, and are used for growth and ripening. The tendrils are curly structures that help the vine cling to the trellis or support system, and maintain its vertical position. The lateral branches are secondary shoots that emerge from the leaf axils, and may produce additional clusters of grapes.
The viticulturists and winemakers have to manage the canopy carefully, to balance the amount of sunlight, air, and moisture that reaches the grapes. Too much shade can reduce the sugar and flavor development, and increase the risk of fungal diseases. Too much sun can cause sunburn or dehydration, and affect the color and aroma of the grapes. To achieve the optimal canopy, they may use various techniques, such as:
– Tying or tucking the shoots to the trellis wires, to keep them upright and organized.
– Thinning or removing excess shoots, leaves, or lateral branches, to reduce overcrowding and improve ventilation.
– Topping or trimming the tips of the shoots, to limit their growth and redirect the energy to the grapes.
– Spraying or dusting the vines with organic or synthetic substances, to protect them from pests and diseases.
Flowering
Flowering is the next major stage in the vineyard, usually occurring in May or June in the Northern Hemisphere, and November or December in the Southern Hemisphere. It happens when the tiny green clusters of flowers on the shoots open and release pollen. The flowers are hermaphroditic, meaning that they have both male and female parts, and can self-pollinate. However, they may also rely on wind or insects to transfer pollen from one flower to another. The pollination process leads to fertilization, which results in the formation of seeds and berries. The berries are initially hard and green, and contain high levels of acidity and tannins.
Flowering is celebrated in various ways around the world, often with music and dancing. For example, in Germany, the Blütenfest (Flower Festival) is held in several wine regions, featuring parades, concerts, and wine tastings. In Italy, the Festa dei Fiori (Flower Festival) is celebrated in many towns and villages, with floral decorations, folk performances, and local delicacies. In Argentina, the Fiesta Nacional de la Flor (National Flower Festival) is held in Escobar, a town known for its flower production and nurseries. The festival includes a flower parade, a queen contest, and a display of regional wines.
Flowering is a critical and delicate phase, as it determines the potential crop size and quality. The number of flowers that successfully pollinate and set fruit is called the fruit set, and it can vary from 30% to 70% depending on the grape variety and the weather conditions. Warm, dry, and calm weather is ideal for flowering, as it facilitates pollination and prevents shattering or falling off of the flowers. Cold, wet, or windy weather can hinder flowering, and cause poor fruit set, uneven ripening, or coulure (the failure of the berries to develop after fertilization).
To ensure a good fruit set, viticulturists and winemakers may use various techniques, such as:
– Choosing grape varieties that are suited to the climate and soil of the region, and that have consistent and reliable flowering behavior.
– Adjusting the pruning and canopy management practices, to influence the timing and duration of flowering, and to expose the flowers to optimal sunlight and air circulation.
– Applying plant hormones or biostimulants, to enhance the flowering and fruit set process, and to correct any deficiencies or imbalances in the vine.
In summary, spring is a vital season for winemaking, as it marks the start of the grapevine’s growth cycle. From bud break to flowering, the viticulturists and winemakers have to monitor and manage the vineyard carefully, to ensure the health and quality of the grapes. They have to deal with various challenges, such as frost, pests, diseases, and weather fluctuations, and use various techniques, such as pruning, canopy management, and plant hormones, to influence the flowering and fruit set process.
This article is the first in a series of four articles that dives into the seasons and stages of winemaking, from blossom to bottle and everything in between. In the next article, we will explore the summer season, when the grapes undergo veraison and ripening, and the viticulturists and winemakers prepare for the harvest. Stay tuned for more insights into the fascinating world of winemaking. 🍇🍷
SOMM&SOMM 
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