We have already discussed the topic of the harvest in general in Part 1/2 of our Millesima Tip #3. What follows is a closer look at manual vs. mechanical techniques and the effect of global climate change on wine grape harvests around the world.
Man vs. Machine
Tradition or modernity? Manual or mechanical harvesting? The choice often depends on the difficulty of climatic conditions.
Mechanical grape harvest – carried out by increasingly sophisticated machines – is generally chosen for economic reasons to produce conventional wines, which do not require precise grape selection. While manual harvest often involves a primarily selection in the vineyard, followed by a secondary selection at the winery’s sorting table, mechanical harvest does not. This means a less specific allowance for the quality of grapes used to produce a wine. Today, almost 75% of harvests around the world are mechanical. Such a high degree of preference for this technique can be explained by the speed of the latter as compared to that of harvest by hand. If there is a risk of rain during harvest – a natural occurrence which can prove detrimental to the quality of the grapes – the mechanical technique saves a larger quantity of fruit by guaranteeing hasty delivery to the vatting room. In the South of France, many wineries rely on machines for night harvests in order to help prevent the oxidation of grapes due to the early morning heat typical of this area. While it is possible to harvest grapes manually by night, doing so requires much more time, resources and organisation than using machines.
It must also be pointed out that while mechanical harvest is common all over the world, many appellations forbid this method. This is the case, for example, in the Champagne and Beaujolais regions of France, where the grapes must be vinified whole, which mechanical harvesting does not guarantee.
Manual harvest is closely linked with tradition. Historically, picking grapes was done by hand without any mechanical aid. The use of machinery didn’t even begin until 1971 in the United States and around 1975 in the Bordeaux region of France. While manual harvest has the benefit of more careful primary selection on the vineyard, – in other words, making sure only the best grapes are used in the production of a wine – this method is also much more time consuming and expensive for the winery. The result is generally a smaller yield of higher quality grapes used to produce more exclusive and higher priced wines. Most vineyards practicing wine production with organic or biodynamic production techniques rely solely on manual harvest, since machines can greatly harm the vines and soil, especially when the vine rows are planted closely together or on a steep slope.
The production of sweet dessert wines automatically require manual methods, as the harvest team needs to go through the vines several times and practice extremely careful selection. This is especially the case with sweet wines made of grapes “infected” with botrytis cinerea, like French Sauternes or Hungarian Tokaji.
Global Climate Change: A Blessing in Disguise or the Beginning of the End?
Global climate change seems to be on everyone’s mind these days. And if it isn’t, it should be. This natural phenomenon is predicted to affect almost every sector of business in the world, not excluding the wine industry. In France today, grapes are harvested an average of one month earlier than they were in the 1950’s. The increased occurrence of hot and dry vintages results in a higher overall concentration of sugar in the fruit, which leads to wines that are higher in alcohol – sometimes even too high. There has been much research carried out, in regions earlier affected by these climate changes, on how to decrease alcohol level without affecting the aromas and flavour profile of a wine.
Be that as it may, there is no denying that grapes today – wherever they are planted – more often reach optimal maturity, which explains why there are more vintages of higher quality. In some cases, this early ripening can change the aromas and favours of the grapes (and, as a result, the wine) so that they are no longer characteristic of an appellation. As early ripening grapes lose their acidity early on, the wine produced from them will have a lower ageing potential.
And while some areas – notably Southern England – benefit by becoming warm enough to allow for the cultivation of grape vines, other regions historically known for wine production may suffer. Some hot weather wine regions may, for example, become too hot to continue growing wine grapes. Other regions, such as those in the north with a “fresh” climate might witness their temperatures rising while humidity remains the same, with detrimental effects on wine production.