The greenhouse effect in grapes growing: Nellaserra method
“At Villa Mari Vineyards the best wines come from the ripest grapes. Just like planting grapes on south-facing slopes to increase their exposure to the sun, they employ a few little tricks to make sure they end up with the ripest possible grapes each year.
One of those tricks is to set up temporary greenhouses over the grapes in order to create warmer temperatures during the day and extend their growing season. It seems like common sense, but it’s a technique that is actually fairly new to winegrowing in the area. There is still a lot of work involved – usually in making sure the grapes don’t get too warm – but the benefits are numerous.
Thanks to the warmer daytime temperatures, they estimate that grapes have roughly 4 weeks of extra time to develop and ripen. In addition, thanks to northern Michigan’s cool nights, those ripened grapes are able to preserve their refreshing acidity.”
“The nellaserra™ approach to grape growing comes with a stiff price tag. Lagina estimates the cost of installation alone at $30,000 per acre. For this reason, only the winery’s premium wines will be grown under sheltered conditions.
Lagina says they are still tweaking the bottle prices, but the range will likely begin in the low-teens and reach upward to $60 for hoop house varietals. He said the warm days and cool nights typical of our region will lead to intense flavors in the wine, and the high tunnels will only magnify this effect.
The shelters come with side curtains that can be raised and lowered to control heat and humidity. Other side benefits of the nellaserra™ method: fewer pesticides are needed and the grapes tend to “short crop” themselves (fewer clusters mean lower yields, which tend to benefit overall wine quality).
The “greenhouse” effect, however, cannot work miracles. During the Polar Vortex of 2014, even Villa Mari experienced winter damage. According to Lagina, it reached -15º F over several days on the peninsula.”
“In terms of his winemaking enterprise, the proof, as they say, is in the pudding and Lagina’s wines, vinified by Sean O’Keefe, have earned him plenty of loot in the form of shiny medals.
Following the 2014 San Francisco Chronicle Wine Competition, Villa Mari walked away with three silver medals for their 2010 Praefectus, 2010 Ultima Thule and 2010 Row 7 blends. Row 7 is a “mystery” red blend, the result of a chaotic but serendipitous planting session. Praefectus contains Cabernet Franc (76 percent), Cabernet Sauvignon (22 percent) and Syrah (2 percent). Ultima Thule (pronounced Toolie) is a blend of Nebbiolo, Syrah, Cabernet Sauvignon, Merlot and Malbec.
Other Villa Mari wines include Solo Nove, Bel Tramonto (a Merlot/Sangiovese blend) and a straight Cabernet Franc. Ultima Thule and Row 7 are both produced using the nellaserra™ method.”
“Whether Lagina’s nellaserra™ method catches on with other local wine growers remains to be seen. For the time being, his greenhouse effect will create the best kind of climate change, transforming his corner of Old Mission Peninsula into an authentic Italian cantina, subterranean cave, oak barrels and all.”