The harvesting machine, a gain in time and money at the expense of quality?
Created in 1971, the harvesting machine is a tool which allows winegrowers to mechanically pick up grapes. Despite popular criticisms linked to the machine’s lack of delicacy and care when handling grapes and vineyards, it allows producers to save considerable amounts of both time and money. The sanitary crisis, the losses induced by covid-19 and the lack of foreign workers have concomitantly contributed to the harvesting machine’s comeback for the 2020 harvest.
I – The harvesting machine: how does it work and what are its benefits?
1 – The machine’s mode of operation
The harvesting machine is similar to a viticultural tractor, whose aim is to pick up grapes through a vibration system. The machine is composed of a harvesting head, a conveyor belt, a cleaning system and a storage system. The machine goes over the vine rows (like a traditional tractor), a system of “picking arms” shakes, beats and whips the vegetation in order to make the grapes fall over a recovering mechanic carpet. A vacuum cleaner then removes all insects and branches from the carpet, to only keep the grapes. These are then placed in a storage hopper, before finally being transported to a wine cellar. Different models of harvesting machines exist, some of which may sort different types of harvests depending on the grapes’ sizes.
2 – A money and time-saving tool
A harvesting machine makes it possible to carry out a harvest in a record time: a machine only takes up to 2 hours to pick up 1 hectare or vineyards against 63 for manual harvesting. Alain Savary, Axema’s director, a French workers’ union for agro-equipment industrialists, explained during a visit in Mas-Thibert located in the Bouches du Rhône region that “They are only 3 people to harvest 200 hectares in a few days. If work was carried out manually, it would take a hundred people at least to undertake similar tasks in the same amount of time! With machines, harvest can be done during the night and then brought directly to the wine press. In short, it’s much more efficient!”. In addition, a harvester’s cost, for a wine producer, corresponds to twice that of a machine. Moreover, these numbers do not fully reflect the reality of the harvest period for wine producers. It represents a stressful period of time for them: they have to feed, house and manage dozens of pickers, supervise the work in vineyards as well as in cellars. All of their efforts are rewarded by sympathetic and friendly moments. Nevertheless, the 2020 vintage is marked by the health crisis. The health authorities have published recommendations for the harvest that make them more restrictive, such as limiting the number of people per vehicle or requiring one picker to be housed per room.
3 – France, a market leader in harvesting machines production
Despite the fact that many French winegrowers criticize the use of harvesting machines, France itself holds an important monopoly over their production. The country produces 99% of harvesting machines around the world. Admittedly, this remains a quite niche market. However, this market equally represents an annual turnover of no less than 200 million of euros (the average price for a machine being 200 000 euros). The main harvesting machine buyers are the “new” wine-producing countries (Argentina, Chile, United States) as well as Spain, Germany and Austria.
II – A heavily criticized tool
1 – Impact upon grape quality
Harvesting machines undeniably represent a gigantic gain in terms of both money and time, however it does not always guarantee high quality. Grapes are much more crushed than during manual harvests, which negatively impacts the plant as well as the wine.
Impact upon the harvest
A mechanized process of harvest does not separate the foliage, branches, insects or gastropods. It is therefore necessary to sort out the grapes from the rest after a mechanized harvest, before the grapes’ vinification. The harvesting process also contributes to the grapes’ premature oxidation, a flaw that frequently occurs in white wines, as berries are roughly shaken by the machine, which causes the skin to break and thus releases the juice. With a harvesting machine, the final result which is brought to wine cellars often consists of a mixture of berries and juice. For this reason, macerating not only the grapes only but the whole bunch, with the plant’s stalk (the vegetal skeleton of the bunch) is impossible for red wines.
When it comes to a manual harvest, rather than a mechanized one, berries are crushed in a press, after a manual selection. In contrast, a harvesting machine does not operate any type of grape selection. Grapes which have not ripened yet are therefore not taken out from the harvest and their juice is mixed in with the rest.
Mechanical harvesting does not suit all kinds of grape varieties, as some grape varieties’ vine stalks and berries are more fragile than others. The grapes’ size and density must also be taken into account when considering mechanical harvesting. Based on this, some grapes varieties, such as Cabernet Sauvignon, Cabernet Franc, Merlot or Mourvèdre, are easier to harvest mechanically than Gamay or Pinot Noir varieties as their grapes are more fragile. In terms of white wine, Riesling grapes will be much easier to mechanically harvest than Sémillon grapes for instance. For the production of sweet wines, it is practically impossible to consider mechanical harvesting, as these types of grapes are incredibly small and do not fit the machines.
Long term impact for the vines
Moreover, mechanical harvesting causes long-term damage on the vines, whereas manual harvesting doesn’t. Repeated use of harvesting machines reduces the vines’ life span.
2 – A tool which is not always adapted and often forbidden
The harvesting machine is not adapted to all type of vineyards.
For plantations grown and harvested on hillsides or steep slopes, a harvesting machine is an ill-suited tool. This is the case for the vineyards in the northern region of the Rhône Valley like Condrieu, Côte Rotie or the Hermitage hill. Additionally, some vine techniques, such as the Gobelet-trained vines, prevent workers from using harvesting machines. Regions which produce gamay, syrah or Mourvèdre wines mainly use this specific technique.
Its use is prohibited by the appellation d’origine contrôlée (AOC – “controlled designation of origin”)
The harvesting machine does not put in place the healthiest types of harvest and induces a quality loss. For this reason, certain AOC rules, a French certification granted to certain prestigious wines, prohibits the use of harvesting machines. This is the case in the Champagne region, which produces high-quality wines and does not want, under any circumstances, to use mechanical means of production. This is largely due to two reasons: on the one hand this allows the region to maintain its reputation and on the other, to preserve high quality products’ production. Another issue resides in the fact that one of the region’s common grape variety, the pinot noir, a red grape variety which gives a white juice, will not produce white wine if harvested mechanically. The Beaujolais region also prohibits mechanical harvesting. In this region, AOC rules require grape bunches to be picked and fully vinified, which is impossible with machines. Moreover, certain AOC rules allow mechanical harvesting techniques but these methods are still rarely used.
Proof that mechanical harvesting’s prohibition is still synonymous with quality today : the Saint-Emilion’s AOC specification authorizes it, in contrast to the Saint Emilion Grand Cru, which doesn’t. This is the case for prestigious Bordeaux wines’ AOC specifications (Pauillac, Saint-Estèphe...), and many AOC Burgundy wines.
The harvesting machine remains an essential tool for the production of modern wine.
To conclude, the harvesting machine presents many assets, its modernization continuously improves the quality of grapes being collected each year. For this reason, the harvesting machine is used in 90% of harvests worldwide. Its use is not too expensive, and it remains a very useful tool in the production of affordable wines, especially wines under 10€.
Thanks to these their recent modernization, the grape harvesting machine presents better assets than traditional grape pickers (price, speed, 24-hour use) for the production of red and white wines which do not require whole bunch vinification. However, they will never truly replace the high spirits of a team of grape pickers.