As grapes vibrate across the MOG separating table, seeds and shot berries fall through the screen. The bar in the front is a newly added air knife to remove light material as the grapes fall.
The relatively new processing station at Chateau Ste. Michelle’s Canoe Ridge Estate winery—with its one-of-a kind system for removing material other than grape—has an impressive list of attributes. Unloading and receiving grapes is way faster, more material other than grape (known as MOG) is removed, and grapes are handled more gently. But the bottom line is that wine quality is improved, say Chateau Ste. Michelle winemakers.
The 2010 crush was the second season the processing station at the Canoe Ridge winery received grapes. The red-only winery, near Paterson, Washington, is where all red winemaking for Chateau Ste. Michelle takes place. Speed and scale are needed to process more than 8,000 tons of grapes during crush, most of it in a three-week period. Last year, the facility handled 8,300 tons, but the receiving facility could easily process double that if there were no limitations on fermentation tanks.
“It’s all about improving wine quality and that starts with how the grapes are processed,” Chateau Ste. Michelle Winery’s head winemaker Bob Berthau stated in an earlier news release. “It will have a huge impact on the quality of our red wines moving forward.”
Softer tannins
Chateau Ste. Michelle red winemaker Joshua Maloney, who joined the Ste. Michelle winemaking team in 2005, said that one of the criticisms of their wines has been that the tannins were too abrasive. It’s a unique problem that he didn’t experience as a winemaker in California.
“Bob Berthau and I never saw tannins this big when we were in working in California. It was a shock to both of us, just how robust these wines can be,” said Maloney, adding that it was standard there to leave skins on the grapes for 21 days compared to 6 or 7 days in Washington. “It’s just night and day. The tannins we have in Washington are exceptional, but they’re also ample.”
The red winemaking team at Ste. Michelle has been zeroing in on techniques to soften the tannins during fermentation, weeding out the “bad” tannins. Maloney said they identified two things they believed would improve wine quality: increasing the amount of whole berries sent to fermentation; and removing additional MOG. “We wanted to get as much whole berry as we could. Cut marks on the skins are where some of the harsher tannins were coming from. The goal was to get fruit in the tank as gently as possible.”
They were getting about 20 percent whole berries and removing 1.5 percent of stems and other debris during the destemming process from a truckload (20 tons) of grapes “on a good day.” The destemmer was the only process they used to remove MOG. Maloney said that anyone who has chewed on the seeds from seeded table grapes knows what he is talking about. “This stuff
The new MOG monster, as it’s referred to, has increased the amount of material that is removed to 2.5 percent per truckload. In a 20-ton load, that’s an additional 1,000 pounds of MOG now being removed. “Before, that 1,000 pounds was going to the fermentation tanks,” Maloney said. “It may not sound like a lot, but two and a half percent over 8,000 tons adds up.”
Specialized equipment
When Maloney and project administrator at the Canoe Ridge winery, Ryan Grenell, got the green light to upgrade the grape receiving facility, they asked for bids from several vendors. The new system needed speed to handle 70 tons per hour, deliver 40 percent whole berries, and they wanted to increase the amount of MOG removed.
Grenell noted that their old system required the grape must to be pumped vertically 25 feet to bring it to the top of fermentation tanks. The 25-foot lift was exerting more pressure on the grapes than the presses and needlessly adding to maceration of the grapes. By redesigning the entire receiving station, pumping vertically was eliminated. An incline conveyor belt now lifts the grapes to the destemmer and MOG table, and the must is piped horizontally to the tanks. A large, slowly moving auger gently moves grapes from the receiving hoppers to the conveyor.
P and L Specialties of Windsor, California, proposed using their MOG separator table on a never-tried-before scale, with the assurance that if it didn’t work, Ste. Michelle wouldn’t have to pay for it, Maloney said. “That was the selling point. We’d seen their MOG tables, but that was looking at a toy size, handling about two tons per hour. They’d never done something at this scale.”
Since installation, they’ve had a California winery visit and have had several inquiries from Washington wineries regarding their MOG monster and new facility.
“Taking a handmade winemaking style and getting it into fermenters at that speed was something we didn’t think was possible. We didn’t think the two could go hand in hand,” said Grenell, adding that they had never considered using a MOG separator because such equipment was not large enough to handle their volume.
An air knife was added to the equipment this year, shooting a stream of air sideways across the grapes as they drop from the MOG table into the must pump. The air knife blows out light material missed by the MOG screen.
Another feature of the crush pad is a heat exchanger that warms up juice as it is collected during crush. “One of the keys to effective destemming for machine-picked fruit is to dejuice as much as you can before the grapes go to the destemmer,” Maloney said. Juice is collected off the grapes before they go to the destemmer and after going over the MOG table.
Sending juice through the heat exchanger before it goes to fermentation can raise temperatures by 20° to 30°F, raising the entire fermentation tank by 5 percent, Maloney said. “When fruit is coming in at the end of the season just above freezing—when every second counts—the heat exchanger can cut 12 hours off fermentation times.”
Turnaround time
As they redesigned everything about the receiving station, Grenell noted that they moved the system north by 30 feet to give the trucks more room for turns. “We tried to think of everything in the whole system—where the bottlenecks were and how could we improve everything.”
The new station can process four truckloads in an hour, about one truck every 11 to 14 minutes.
The winery’s previous 24-hour record of processing grapes was 352 tons. Last year, right before the October 11 freeze, the facility handled 850 tons in a 28-hour period.
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