It is one of the most common questions around the tasting room and on tours. And for good reason…there isn’t a real quick answer. Generally speaking there are two methods of getting the fruit off the vines – hand picking and machine harvesting.
In 2012 we hand harvested somewhere around 70% of the vineyards. This was due to several factors, including some mechanical problems for the aging harvester. But the main reason we hand pick is to preserve the integrity of the fruit, which can lead to better wine. To elaborate, let’s start with a brief overview of how the mechanical harvester works.
The mechanical harvester works by driving over the row. There are nylon arms that vibrate and shake the fruit loose (shown to the right). Then a series of conveyors move the grapes to an adjacent row where they are deposited into a bin box carried by another tractor. The grapes are actually shaken right off the stems, so the bin boxes can easily exceed 1 ton of grapes each!
Mechanically harvesting is generally more efficient. It can be done with a team of 4 workers, and in the middle of the night, which makes it easier to schedule around cellar needs, weather, etc.
So if it’s so efficient and flexible, why don’t we mechanically harvest more?
There are several reasons we might choose to hand harvest. Some varietals don’t shake off the stems easily, so the plants would have to be beaten senseless in order to get the grapes off. Aside from being hard on the plants and the trellis, it’s also potentially bad for the wine.
The quality of the wine is actually the main determinate of harvest technique. When the harvester shakes the grapes loose, lots of them end up breaking open. This can be mitigated by running the machine slower, but it’s inevitable. When you’re making white wine, particularly a delicate flavored wine such as Sauvignon Blanc or Pinot Grigio, that contact between the skins and the juice can add undesirable bitterness to the final product. By hand harvesting the grapes arrive at the press pad largely intact, taking pressure off the cellar crew to get them crushed and pressed ASAP. This is particularly important if the grapes were harvested off the estate, since they have travel time between harvest and pressing.
For some products the bitterness isn’t much of a concern. These tend to be sweeter wines where the residual sugar masks the bitterness, or styles where the flavors are simply less delicate. Or, they are red wines. Red wine ferments with the skins and seeds to extract color, flavor and tannin, so logically a couple extra hours of skin contact is totally fine.
The process of harvesting requires a lot of careful coordination between the farm and cellar, regardless of the techniques used. Though we still have a few loads to receive from other growers in the Lake Michigan Shore AVA, all of the Fenn Valley estate fruit is picked. In talking with Todd, our farm manager, it’s a HUGE relief each year. But there’s no rest for the weary, work is already in progress on the 2013 vintage!