Colin Burbidge, of Lancashire Wine School, writes about the weather conditions to make the perfect wine.
English wine-makers are currently buzzing about this year’s harvest following the bumper summer weather.
Other European wine regions are making good noises, too.
Nytetimber in the south of England has declared this a fantastic vintage, yet the wines won’t be available for drinking until 2022.
Many things impact the final quality of the wine, which means wines will change from year to year.
Note, the year a wine is produced is referred to as the vintage.
The weather conditions during the growing year are most important. The amount of heat, sunshine and rainfall during a year changes the nature of the grapes produced and therefore the wines.
This is known as vintage variation. This can be seen as separate from factors such as climate, soil, vineyard techniques which are largely constant year-to-year.
Warmer climates have more consistent weather conditions, so there is little vintage variation.
In cooler climates changes can be more marked, and it is here the vintage variation can be more of a challenge.
The effect of weather can be different at different parts of the year.
During springtime, low rainfall and frost levels are desirable to allow the vine to start to grow and for the berries to form. During summer, warm and dry conditions allow the grapes to build up flavour and sugar and start to increase in size.
Too much or too little heat or water will cause problems with ripening. Over autumn, when
harvest is occurring, again low rainfall is ideal, as high levels can lead to mould growing on the bunches or dilute flavours in the grapes.
The grapes are harvested when they have the optimal balance of sugar, flavour and tannin ripeness. This can be a hard time to pinpoint, and even when you have decided it, you need to have enough people or machines available to get the job done!
So when talking of a good vintage if often means the optimal combination of all these things: A fairly settled spring time where the vine has been uninterrupted in flowering and fruit-set, so there are a good number of berries. A warm and dry summer with a little, but not too much, rain and warm, but not too hot, conditions will ensure good ripening and sugar levels and a good balance of flavour and tannin ripeness. And then a dry autumn will mean that berries remain healthy, unaffected by rot or mould and fill with just the right amount of water. The result would be a good-sized crop of perfectly ripe grapes that would make a wine with structure and concentrated flavour.
There are many ways to check the health of the grapes. The old-fashioned way of eating grapes from the vine to assess acidity, sugar, tannin and ripeness levels is still used widely today.
More precise scientific tests are often applied to confirm the ‘taste-test’ results.
Since the grapes are the key ingredient in our wine production their health is of utmost importance… you can’t
make a silk purse from a sow’s ear! However, things can still go wrong in the winery, so you can never be totally sure until you taste the finished product.