On Palate Press: Machine vs. hand-harvesting (and our future with robots in winemaking)

A few years back, a group of Auckland-based researchers established that machine-harvested Marlborough sauvignon blanc has higher aromatic thiol concentrations = tastes more intensely Marlborough sauv blanc-y = is better than wine from hand-harvested grapes. I don’t know how widely that logic is known amongst wine consumers, in New Zealand or elsewhere. Reading back labels in my local wine shop makes it clear that the hand-picked grapes = superior wine logic rules in the minds of marketers and, if they’re any bellwether (a worthwhile question), at least some consumers.

Marlborough sauvignon blanc aside, is that prejudice justified? My January piece for Palate Press addresses that question. The short answer is that hand-harvested grapes are in many settings more about feeling good about purchasing genuine artisan wine than about quality or flavor. The longer answer is here.

Saying that hand vs. machine harvesting is becoming less and less of a quality issue, with better equipment in the field and in the winery, isn’t the same as saying that the difference doesn’t matter. It does, to our perceptions of what we drink. But it’s also impossible not to see this as one more instance of Robots Will Take Our Jobs, and a particularly hard-hitting one with wine such a cultural icon. A lot of vacuous dithering takes place in the media around this topic (even in outlets like The Atlantic, though this piece from The Economist might be an exception) and, to be honest, I’m not sure that I have anything worthwhile to add. We’re headed, I think, for a major shift in how people work, earn money/obtain necessary resources, and spend their time. That shift may come in the form of an organized political (maybe governmental, maybe by large companies) decision to redefine work and money, or it may come as a necessary post-degenerate organic movement after the fall of Rome. Either way, being human, we’ll continue to find meaning in our work whether that means choosing to harvest grapes by hand because it’s meaningful to do so, even when a machine/robot can do a better job, by redefining wine quality such that the robot can’t do the job as well, or by understanding human winemaking as a conceptual art independent of the physical work of our hands.


8 thoughts on “On Palate Press: Machine vs. hand-harvesting (and our future with robots in winemaking)

  1. The grape harvester was invented in New York by (among others) a grape grower named Roy Orton in the late 60s, and New York growers have been machine harvesting grapes for at least 40+ years.
    One quality issue: Machine-harvested fruit can often get from vine to crush pad faster, where lugs full of hand-harvested fruit could be sitting in the vineyard for a sizable amount of time. Score one for machine harvest.
    Another one: It makes night harvesting a lot easier and safer. Score another for machine harvest.
    Disadvantage: You can’t do whole-cluster pressing.

    It makes harvesting a 5 acre block into a couple of hour effort, instead of either a giant crew or 2 day effort.

  2. I like it.

    Not sure we need to have “either or..”. I imagine we will get them all. History will no doubt sort through after and allocate the answer(s) but we are undoubtedly living through what will be called the “?????????? Revolution”.

    “Post Digital” maybe? Nothing surer than it’ll come out of left field.

  3. While interning in Sonoma County at a mid-size winery, grapes came to the CRUSH PAD in large trucks as either hand-picked or machine picked. The machine picked grapes were closer to ambient air temperatures vs. 10 degrees higher for hand-picked grapes. My thought was that it took longer for hand-picked grapes to be gathered in large enough quantities in order to be trucked from vineyard to winery. As a result, biological activity from rogue yeasts and bacteria began and increased the grape temperature by 10 degrees or so due to biological heat. I also noticed that “Material other than Grapes” (MOG) was higher in hand-picked grapes with more rocks and such with the hand-picked grapes. I think that happened since grapes were paid by the pound. Although there was more juice in the bins of the machine-picked grapes, it did NOT appear to affect the de-stemming and crushing process. I think it is very essential to get those grapes to the CRUSH PAD as soon as possible once the grapes are picked. Therefore, I believe that machine-picked grapes produce on a general basis a better quality wine since rogue biological activity is minimized. Once grapes are picked and osmosis is not occurring in that grapes to keep the yeasts and bacteria out, then the fermentation begins. Regardless of how the grapes are picked, those grapes are busted out from their skins on the CRUSH PAD. The end result is that the grapes are bruised, broken, juiced on the CRUSH PAD so why take care to protect the grapes with hand-picking?

    • You raise some interesting points, Ron. I’d guess that the hand-picked grapes came in warmer (10F, not 10C?) because they spent longer out in direct sunlight and not because of microbial activity. If the hand-picked grapes are intact, why would microbes multiply radically more after picking than when the grapes are on the vine? I’d say that the machine-picked grapes are actually more susceptible to microbial growth on their way to the crusher because some of those sugars that had been tidily sequestered inside the grape are now mixing with microbes growing on the outside of the grape skins to the extent that crushing occurred during harvest. That’s usually not a problem, though, because it takes so little time for grapes to move from vineyard to crush pad (and if they’re being transported any significant distance, they’re often treated with SO2).
      Growth curves of mixed microbial populations at the beginning of fermentation tend to show non-Saccharomyces species in the lead but growing very moderately for the first few hours and then Saccharomyces — commercial inoculated or wild — taking over pretty rapidly thereafter. It would be interesting to see those sort of curves for various machine vs. hand-harvested grape scenarios, as much for folks who are looking for native microbial growth and mixed populations as for those who want the inoculated yeast to take over as quickly as possible. Good questions.

      • Your assumption is correct that the temperature increase in the grapes was based on Fahrenheit. The grapes were placed in stainless steel bins of four feet in height which does allow for compression on the grapes densifying the lower grapes, causing some juice to be emitted. Grapes were places in a heavily treed area with uniform shade and weighed/consolidated from smaller field bins to the larger bins which were trucked to the winery within five miles. There was some juice from the hand-picked grapes and considerable more for the machine-picked grapes. Temperature was measured in a 500 ML tall petrex flask (not sure of technical term) using a mercury based thermometer. The juice temperature, pH, and Brix were measured for each bin and recorded. I hope that might add some clarification to my earlier broad statements.

  4. Saying that hand vs. machine harvesting is becoming less and less of a quality issue, with better equipment in the field and in the winery, isn’t the same as saying that the difference doesn’t matter. It does, to our perceptions of what we drink. dstar

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