We arrived at the beginning of the grape harvest here in Bordeaux, and no sooner than the first week of class got involved in the action.
Bordeaux Sciences Agro (the school I’m attending) has it’s own vineyard and winery in the Pessac area of Bordeaux called Château Luchey-Halde (click here). It’s a full-scale (10,000 case per year) revenue generating operation, but also a training ground for students. We got a tour of the crushing operation, which included a sorting line and a rather clever conveyor distribution system that pivoted around to the fermentation tanks laid out in a circle around the winery.
Grape sorting removes undesirable (shriveled, moldy, or split) grapes/clusters, or other junk (mostly leaves) prior to the grapes going for fermentation. Particularly in larger operations, this step is skipped due to the effort/cost involved. It’s more common in smaller, higher-end wineries. But based on my experience, it seems grape sorting is performed more often here in Bordeaux than at similar sized wineries in California. Perhaps it’s the greater disease pressure in Bordeaux (e.g. molds and rot) associated with the wetter climate. Just a guess…
These sorting processes vary by winery, but at Château Luchey-Halde the first step involves harvested clusters being dumped from picking bins onto a vibrating conveyor table, with rotten or mold covered clusters manually removed by workers. Next the remaining clusters are fed into a de-stemming machine, which separates the berries from the cluster stems without crushing them. The intact berries are then sorted again and fed by conveyor to be lightly crushed just before entering temperature controlled stainless steel tanks for maceration and fermentation. It was interesting to see the care taken during the harvesting and sorting process to avoid breaking open the berries and exposing the pulp and juice to oxygen. This can oxidize the juice and contribute to undesirable chemical and biological reactions during subsequent steps in the process.
The following weekend our class was invited to help with the harvest at a small (400 case per year) family chateau in the St. Emillion area of Bordeaux. They had a much smaller operation, with only one sorting table after the de-stemming machine. (I found this operation particularly interesting, because they served us an absolutely wonderful French country style lunch afterwards in their old stone farmhouse.)
And last week Lynn and I visited a larger chateau (30,000 case per year) in the Entre-Du-Mers area of Bordeaux where they just started using an innovative berry flotation system, which sorted individual berries by sugar content after initial hand sorting and de-stemming. (The sugar content in the berries is what’s fermented to alcohol and one indicator of ripeness and quality.) Because sugar dissolved in water increased its density, riper berries sink, while less ripe berries float. Very clever device (sorry no pictures)…but I wonder how it affects some other important components in the resulting wine. Components such as acidity and pH aren’t necessarily correlated with sugar content. But we’ll find out later, as they offered to host our class for a tour with the winemaker. Already networking!