Hot Summers and Ageworthiness

In many parts of the world, the growing season this year is hot. Not just warm, but hot. Of all the wine areas, the heat seems to have hit the US Pacific Northwest (Oregon and Washington) and perhaps British Columbia in Canada more than anywhere else, but many places are meaningfully warmer than recent norms for the areas. How will this affect your ability to age wines?

To understand this, it's important to recall the 4 key elements of ageworthiness. Each of these tend to make a wine more ageworthy, but, of course, only a quality wine will age well to begin with.

• Higher tannins
• Higher acidity
• Higher sugar content
• Lower alcohol content

So, how does the heat affect each of these?

If anything, tannic wines become more tannic during warm growing seasons. The thicker-skinned grapes that have more tannins tend to be more resistant to the extreme heat. That's a plus for ageworthiness.

But, the more acidic wines tend to like cooler weather. In fact, many of the most acidic wines are made from grapes grown in areas where temperatures during growing season are more likely than not to be below 20C/68F in the warmest parts of growing season. Extreme heat will take a toll on acidity.

Sugar content in wines can be found in two areas: the natural sugar in the fruit and the residual sugar left after fermentation. Typically, the sugar in the fruit increases with ripeness from heat, but the ability to retain residual sugar often increases with cooling. This one is a mixed bag.

Extreme heat produces wines with more alcohol. You just can't undo the chemistry. This could be an extreme negative for the ability to age a lot of 2021 vintage wines.

In any case, 2021 in many parts of the world is going to be an unusual vintage. There will be some extraordinary wines that make great use of the warming, but there will be some horrible wines that cannot handle it. When you buy, buy with caution having been well educated.