When, why and how does the wine grape harvest happen?
With grape harvest season nearly upon us and the celebrations that go with it about to ensue, we’ve been asked what’s involved in harvesting grapes for our world class wines. To explain in more detail, here is your Clos19 insider’s guide to when, why and what happens at grape harvest time...
An anxious wait
For several months of the year, winemakers all around the world face nerve-wracking growing seasons, where just the right amount of sun and rain are needed to grow grapes of the highest possible quality. A close eye is kept on the weather for frosts, heatwaves and hail in particular, which can decimate a vineyard in minutes. In Europe, we’ve had all of these things this year, so spare a thought for our stressed out winemakers. It’s no wonder that when a harvest finally happens, the world’s wine regions are alive with festivals and celebrations! It’s a great time to be visiting one.
Grape picking (or grape harvesting) is the first step of several in the winemaking process. For ‘normal’, still wines, this usually happens at the turn of Autumn which, in the northern hemisphere, can mean any time between the end of August and as late as mid-October. In the southern hemisphere, it’s all the other way round, with harvests usually happening from late February to April. ‘Late harvest’ and ‘Ice wine’ grapes rely on a longer hanging times (on the vines), so are often harvested a few months later.
During the growing period, grapes are checked carefully throughout the days until ideal levels of acidity and sugar ripeness are reached for the desired style of wine. The amount of natural sugar in the grape is responsible for the final alcohol level as well as how dry or sweet the wine is going to be. The ‘phenolic’ or physiological ripeness of the grape is also key; this refers to the colour of the skin, pips, stems and how the tannins taste in the mouth. Grapes for sparkling wines are picked a little earlier than for still wines as they need a higher level of acidity and less sugar. It’s worth noting that many wine regions with designated rules such as AOC or IGP, will issue strict rules to adhere to for all of the above.
Tastebuds or technology?
How do we know when a grape has reached the perfect level of ripeness and is ready for harvest? Well, technology helps, but simply tasting the grapes from various parts of the vineyards (when done by seasoned pros) can tell you a lot, especially as grapes from different locations ripen at different times. To confirm actual sugar levels, a simple device used as a ‘refractometer’ can be used, which measures the amount of sugar in grape, known as the ‘brix’ level. Laboratory tests are increasingly used too to test this as well as acidity and phenolics.
Harvest by hand or machine?
How the grapes are physically gathered is up to each individual winery. Hand harvesting is a much gentler process than machine harvesting, though it’s a lot more time consuming. This is one reason why fine wine can be a bit more expensive. Machine harvesters are a lot better now than they used to be, though, and they allow the winery to pick their grapes rapidly.
The final stage in the grape harvest process is to sort the grape bunches, removing the rotten bits and other debris before the wine is sent to be pressed. Et voilà! On to the next phase...