Rain in the spring and at harvest time can be detrimental to a wine's vintage.
Tristan Roznowski

Tristan Roznowski

May 19, 2021  |  4 mins read
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What is Vintage and Why Does it Matter?

Rain in the spring and at harvest time can be detrimental to a wine's vintage.

Of all the facts and figures listed on a wine label, the vintage—that is, the year the grapes were harvested—is perhaps the most overlooked. The date is not always prominently featured on the bottle, nor is it as evocative as other information such as the region or producer. 

However, vintage is a major determinant of a wine’s quality and characteristics; it tells the story of a single growing season, influenced by specific climatic conditions and shaped by the various tools and techniques used by a winemaker.

So, what makes a good vintage? Does age matter? And how does weather factor into things? 

Like other agricultural products, the weather affects a grape’s quality and taste. Climatic conditions influence a vine’s behavior and lend structure to the fruit. A rainy episode before or during harvest, for example, will fill the grapes with water. The proportion of water in each berry will increase while the concentration of other compounds will decrease, diluting the flavor or making the wine flatter and less expressive.

Heat is another factor that influences a wine’s profile. High temperatures tend to intensify the sugar concentration in a grape and produce higher potential alcohol levels, resulting in a fuller-bodied wine. 

Geography, of course, plays a part, and every region has location-specific challenges. Vineyards in southwest Australia, for example, are frequently plagued with sunburnt crops due to excessive sunlight, while wildfires in California have exposed vines to smoke taint. And with global warming, these extreme weather events are becoming more commonplace, forcing winemakers to take drastic measures.

Fluctuations in taste and quality over time are referred to as the “vintage effect.” It’s why grape bunches harvested from the same vine, on the same plot, on the same day—but in a different year—reach the cellar with a different composition, and therefore make a different wine.

Read on to learn more about the climatic conditions that give shape to a wine and discover why balance is everything.

Rain

Water is key to a vine’s revival. The timing and amount of rain impacts the vine and affects a grape’s composition. A rainy vintage can reduce crop quality, while severe drought can reduce yields and threaten the vine’s health. 

The timing of rainfall is also important. Winter rainfall creates a reserve of water that will be absorbed by the vine’s roots during the growing season. But rainfall late in the season or during harvest can spell disaster; grapes that absorb large quantities of water can dilute sugar and aromatic compounds.

Rain can also raise humidity levels, creating conditions conducive to the development of rot and fungus.

Heat

Generally speaking, grapes like warm days, cool nights, and bright sun. When the temperature is too high, or the sun is too intense, it affects the length of a grape’s growth cycle as well as its ripening process. 

Heat is necessary for flowering and fruit-set, two major steps in a grape’s development. Flowering is the growth of inflorescences (a grape flower cluster), and the transformation from flowers to grapes is fruit-set. These events are triggered by temperature and cannot effectively take place below the threshold of 15 degrees Celsius (60 degrees Fahrenheit).

Vintages are often categorized as cool or warm­. Cooler vintages refer to years characterized by colder temperatures and no major heat waves. These wines have higher acidity, more freshness, and delicate fruity and floral aromas. Cooler vintages in cool climates can be problematic for grape ripening, particularly for late-ripening varieties. Low temperatures can delay the vine growth cycle and provide insufficient energy to the shoots during the growth stages. In warm climates, however, cooler vintages often bring an extra dose of freshness.

Conversely, warmer vintages refer to years with unusually high temperatures, often punctuated by regular heat waves. These conditions tend to result in full-bodied wines (due to the sugar concentration in the grape, which can convert into higher degrees of potential alcohol), with jammy aromas of ripe black fruits in red wine, and tropical fruits in white wine. In cooler climates, these vintages tend to have an aromatic profile of more ripened fruit and be less fresh, due to the lower acidity levels in the grapes. 

Light

Sunlight is key to happy grapes. Without light, photosynthesis isn’t possible , and vines won’t provide sufficient energy for grape development. Good vintages are often characterized by long days with minimal cloud cover, whereas a bad vintage can be linked to poor light intensity during the growing season.

Extreme Weather

Drought, hail, and frost are among the extreme weather events that can affect the grape quality and overall health of the vine. With climate change, many of these phenomena are becoming more frequent and more intense, presenting major risks for winegrowing in major parts of the world.

In 2020, big forest fires in the United States and Australia blanketed wine regions in clouds of smoke, exposing grapes to smoke taint. Some effects of smoke taint are reversible but require significant effort from the winemaker to mitigate unwanted flavors.

Frost is another extreme event that frequently affects winemakers in the northern part of Europe, as was the case earlier this spring. Late spring frosts are particularly devastating when they occur after budburst, as the buds are most sensitive to frost at that time. 

So, why does vintage matter? Vintage is a pure representation of what nature had to offer at a particular time in history. It’s part of what makes every wine unique, and also what makes the subject so fascinating and ripe for discovery.Now’s the time for you to witness the vintage effect first-hand. Save your spot in the “Taste the time with Dufort-Vivens” Experience to travel to Bordeaux and listen to Margaux winemaker Gonzague Lurton explain how the character of his wine varies year to year.