Wine Drinking Windows: Understanding the Forecast
Updated
A wine drinking window, often presented as a vintage chart, is a forecast about a wine's optimal consumption period. Its importance is "varied and disputed". A vintage wine is one made from grapes "that were all, or primarily, grown and harvested in a single specified year". Superior vintages from prestigious producers may command higher prices, and they are "likely to improve further with some age in the bottle". The "vast majority of wines are produced to be drunk young and fresh", where vintage is "usually considered less important". Frank J. Prial, a New York Times wine columnist, declared the "vintage chart to be dead". He stated that "winemakers of the world have rendered the vintage chart obsolete". This suggests that a published drinking window is a guide, subject to many variables. It is not a definitive statement about the bottle in your cellar.
What does a vintage tell you about a wine?
A vintage primarily identifies the year the grapes were grown and harvested. That is a crucial detail for understanding the wine's origin and potential. In Chile and South Africa, a vintage-dated wine must contain 75% same-year content. In Australia, New Zealand, and European Union member states, the requirement is 85%. The United States also requires 85%, increasing to 95% if the wine is designated with an AVA, such as Napa Valley. The significance of this year is most pronounced for wine produced in regions at the "colder climatic limits of wine production". There, seasonal variations can lead to "much warmer" seasons producing "riper grapes and better wine". They can equally bring "poor growing season[s]" resulting in grapes "higher in acid and lower in sugar", which affects quality.
For wines like Port, a vintage can denote quality. Port houses make and declare vintage Port "in their best years". However, in many New World regions, growing seasons are "much more uniform", partly due to "systematic and controlled use of irrigation". That leads to less variation between vintages. Despite this, such wines are "regularly labeled by vintage because of consumer demand". The importance of vintage may sometimes be "exaggerated". Bill Marsano states that "winemakers now have the technology and skills to make good and even very good wines in undistinguished years". James Laube of Wine Spectator asserts that "even an average vintage can yield some grand wines". For those interested in the long-term value of such wines, exploring fine wine investment strategies can be beneficial.
How reliable are published drinking windows?
The reliability of published drinking windows, often presented as vintage charts, is a subject of considerable debate. Roman Weil is co-chairman of the Oenonomy Society of the US and a professor at the University of Chicago. He conducted blind tastings to test one hypothesis: that experienced wine drinkers "cannot distinguish in blind tastings the wine of years rated high from those of years rated low, or, if they can, they do not agree with the vintage chart's preferences". Weil's study involved 240 wine drinkers. They tasted wines that ranged from four to 17 years beyond their vintage. He found that tasters "could not distinguish between wines of good and bad vintages except for Bordeaux wines".
Tasters could sometimes make a distinction for Bordeaux wines. Even then, the match between their individual assessments and the charts' rankings was "little better than tossing a coin". When these tests were "replicated with wine experts, including French wine academics", the results were "again the same as chance". This suggests that relying solely on a vintage chart for determining a wine's peak can be misleading. Weil does not consider a vintage chart "unusable", however. He suggests using one to help "find good buys in wine". Wines from years "considered to be worse than average for vintages may be priced far below its actual quality". This perspective highlights that a drinking window can be a tool for value, rather than a definitive guide to peak maturity.
How does storage affect a wine's evolution and drinking window?
The conditions under which you store your wine significantly influence its evolution. They also decide whether it reaches its optimal drinking window. Excessive storage temperatures have a "marked effect on the shelf life of bottled wine", according to AWRI Technical Note TN09. Marais (1986) observed "faulty flavours and decreasing overall quality" in wine after 12 months of storage at 30°C. Temperatures exceeding 40°C can induce "visual and sensory changes to a wine in only a matter of days", as noted by Ough (1986). Ough (1992) further states that any storage place where the temperature "exceeds 25°C for long periods and 40°C for short periods can affect wine quality".
Beyond temperature, light exposure also has "deleterious effects" on wine quality. Maujean and Seguin (1983) demonstrated that "lightstruck" flavour, or goûts de lumière, results from the formation of volatile sulfur compounds. These are believed to come from sulfur-containing amino acids like methionine and cysteine. Riboflavin, or vitamin B2, present in wine, undergoes photo-activation when exposed to light at wavelengths of 370 nm and 440 nm. That contributes to this effect. Dozon and Noble (1989) exposed still and sparkling white wines bottled in green glass to fluorescent lamps. Those wines developed a "statistically significant" lightstruck flavour after 31.1 hours and 18 hours, respectively. The same wines in clear glass developed this off-flavour much faster, after "only 3.3 hours and 3.4 hours, respectively". Direct sunlight is even more damaging. It provides "4286 times the amount of UV-A radiation as fluorescent lamps", according to Gordon Watson (pers. comm. in AWRI Technical Note TN09). That makes exposure to sunlight "more deleterious to wine quality".
The Australian Wine Research Institute (AWRI) recommends that wine be stored under "insulated and/or temperature- controlled storage conditions, which minimise fluctuations in both temperature and humidity". Amon and Simpson (1986) specifically recommend storing bottled wine with the cork in contact with the wine in a "cool (15-20°C), dry location". The color of the bottle glass also plays a role in protection. Rankine (1989) indicates that "amber glass is most effective in excluding wavelengths below about 450 nm". The AWRI notes a disproportionately high number of copper instability cases in wines bottled in clear glass. These cases lead to haze in white wines. Understanding these storage principles is crucial for preserving your wine's quality. It also helps the wine reach its potential within any projected drinking window. You can learn more about optimal conditions in our guide to how to store wine.
The impact of glass color on lightstruck flavour and copper instability is notable:
| Factor | Green Glass | Clear Glass |
|---|---|---|
| Exposure to 40W fluorescent lamps (still white wine) | 31.1 hours for statistically significant lightstruck flavour | 3.3 hours for statistically significant lightstruck flavour |
| Exposure to 40W fluorescent lamps (sparkling white wine) | 18 hours for statistically significant lightstruck flavour | 3.4 hours for statistically significant lightstruck flavour |
| Sensory changes | Decrease in "citrus" aromas, increase in "cooked cabbage", "corn", "wet wool/wet dog", "soy/marmite" aromas | Decrease in "citrus" aromas, increase in "cooked cabbage", "corn", "wet wool/wet dog", "soy/marmite" aromas |
| Copper instability | Less susceptible to haze (implied by AWRI observations) | Disproportionately high number of cases involved clear glass bottles |
Why might your bottle sit outside its predicted drinking window?
Your specific bottle of wine might not align with a general drinking window for several reasons. That holds even for wines from regions known for longevity, such as Bordeaux. Bordeaux wines are known for their "longevity, fairly large production, and an established reputation". That makes them common at wine auctions. Individual bottles can still vary. The inherent "varied and disputed" nature of vintage charts, is a primary factor. As Roman Weil's blind tastings showed, even experts struggle to consistently distinguish between good and bad vintages, especially outside of Bordeaux. Even for Bordeaux, the correlation with charts was "little better than tossing a coin".
Beyond the general unreliability of charts, your wine's unique journey from the winery to your cellar plays a critical role. Storage conditions, as detailed by AWRI Technical Note TN09, can drastically alter a wine's development. Ough (1992) states that exposure to temperatures exceeding 25°C for long periods or 40°C for short periods "can affect wine quality". Similarly, exposure to light can induce "lightstruck" flavour, particularly in white wines. Direct sunlight is significantly more damaging than electric lighting. Even physical damage, such as "Leakage of wine and/or movement of cork stoppers due to thermal expansion of wine", can occur from high temperatures. That affects a wine's appearance and marketability, even if not necessarily its quality. Such issues can also impact wine ullage levels.
These environmental factors matter to your bottle. Two bottles of the same wine from the same vintage could evolve differently if stored under varying temperature-controlled storage conditions. A wine kept in optimal storage is more likely to age as anticipated than one exposed to fluctuating temperatures or light. Therefore, while a drinking window offers a broad expectation, the actual state of your wine depends on its individual provenance and storage history. When you buy wine at auction, understanding a lot's storage history is key. You can explore current market trends and how they relate to specific vintages on our live fine wine market index.
What should you do when a wine enters its drinking window?
When a wine enters its predicted drinking window, it suggests a period when the wine is expected to be suitable for consumption. That applies particularly to wines that are "likely to improve further with some age in the bottle". This window aims to guide you towards enjoying the wine when it is not "past its best". That is a concern for certain wine styles like Beaujolais nouveau, which is "made to be consumed within months of its bottling".
The importance of vintage is "varied and disputed". Roman Weil's studies also found that even wine experts struggled to agree with vintage charts. The decision to open or hold therefore remains nuanced. For wines from years "considered to be worse than average for vintages", Roman Weil suggests using vintage charts to "find good buys in wine". That implies such wines may be priced below their actual quality and could be ready for consumption. Ultimately, the actual state of your bottle, influenced by its unique storage history and condition, is the most important factor. You can consult our drink now recommendations for wines currently entering their optimal drinking period.