After three dry seasons, the 2018 Winelands winter is a delight. The vital rain has come and with it, the much-needed cold conditions. But with serious spring-time frost damage still fresh in our minds and the Western Cape vineyards now surrounded by snow-capped mountains, when does the cold become a problem?In October 2017, some South African vineyards suffered great losses at the hand of white and black frost. But more than the mere temperature, cold damage also depends on the growing phase of the vine and during Spring, the frost killed flower clusters and vine shoots and in some cases complete crops were lost.
During winter, the cold has a different function. After the spectacular show of yellow and orange in autumn, the bare winter vines might look like they are dying. They are, however, in hibernation storing carbohydrates to use when the new growing season arrives. This is also why winter pruning is so important as it carefully prepares the vine for its next growing curve and a balanced yield.
The current snow in the Winelands is very welcome as it ends up in depleted rivers and dams and also because the cold it brings is exceptionally good for the vine. Vineyards needs proper cold conditions to ensure dormancy. Without a proper resting phase, the vineyard stays active and struggles to survive the winter conditions.
Exceptional cold conditions such as frost, snow and sub-zero temperatures, especially in cold climates, can, however, result in the death of the vine. But again it is all about timing. When the cold comes at the end of the growing season, the result can be a unique style of wine!
When a heavy snowfall during the 2013 European wine grape harvest covered the high-lying vineyards in the mountains of the Adige Valley, other than being discouraged, the young Italian winemaker made a unique wine from his Johanniter vineyards. A cross between Riesling and Pinot Grigio, the result was an elegant white “snow wine”, Vin de la Neu.
Also reliant on extreme cold for its unique style and flavours, is ice wine. A dessert style wine produced from grapes that have been frozen while still on the vine, the production of ice wine is naturally limited to countries such as Germany (Eiswein) and Canada where temperatures are low enough. The refreshing sweet wine is the result of water freezing in the berries and therefore a more concentrated sweet flavour. Other than famous sweet wines such as Sauternes, Tokaji or Trockenbeerenauslese, ice wine grapes are not affected by Botrytis cinerea. Healthy grapes stay on the vines until late in the season, waiting for the cold. These wines are usually expensive because of the risky conditions – the cold might come too late or harvesting all the grapes in a short cold spell, might not be possible.
Temperature stays important, even when the wine is in the bottle. Serving your wine too cold can have you miss out on all its beautiful flavours, but at the same time, serving an unbalanced wine slightly colder than usual might hide a wine problem or two… Winefolly offers handy guides as to storage temperature and serving temperatures.
And when you are the one affected by the cold in the shape of the flu, remember wine’s health properties. According to the Daily Mail, enjoying 2 glasses of wine per day gives you a 40% lower risk of contracting a cold!