There won’t be many northern hemisphere vineyards currently looking as green as the one in the picture above. Last week’s record-breaking temperatures – up to 47˚C (116˚F) – in Spain and Portugal mean that most vineyards there will be brown and parched. And over in California, the baking heat and drought conditions have resulted in catastrophic fires; there, the loss of life and homes are of more immediate concern than any damage to the vines.
But, vineyard owners are survivors and, in most places, wines will be made – but how much and what sort of quality? The last time I remember heat close to this year’s was in 2003 when growers had to rush back from their holidays in August to harvest quickly before the grapes shrivelled. That year, many wines tasted ‘cooked’ and lacked freshness and most were past their best much sooner than expected. I fear that, unless we have cooler temperatures and rain soon, 2018 may be the same.
Although grapes need both heat and sunshine to ripen, the prolonged intensity of both this year will result in higher than usual sugar levels leading, potentially, to ultra-alcoholic and heavy, unbalanced wines. The heat will also mean that the grapes will ripen too quickly, giving them little time to develop the complex flavours that come from nutritious minerals and trace elements in the soil. Some vines may shut down completely as a way of protecting themselves, leading to a much reduced crop.
And then, there’s the night time temperatures, which, unusually, have also remained very high, frequently above 30˚C (86˚F). Often, in hot weather, nights are quite a bit cooler. This gives the vines a chance to rest, helping them retain crucial acidity in the grapes. Without this, wines taste dull and flat and will lack that important refreshing character. Acid can be added artificially during the winemaking process to counter this but it’s not as good as natural freshness.
So, with all these challenges, how will 2018’s wines from the affected areas turn out? I suspect they will be variable; some producers will, no doubt, find the key to making something special, but many will not. Perhaps the best option for consumers is to seek out wines from more northerly vineyards, some of which will have avoided the most extreme temperatures and so the worst of the problems.