Growing & Winemaking


Blown Away

January 2009
by Paul Franson
grape sorting
All red grapes fermented by Provenance Winery go through the Mistral 140 automatic sorter, says winemaker Chris Cooney, who installed the device at the Rutherford, Calif., winery in 2007.

  • Word of mouth is responsible for the popularity of automatic sorting tables, which eliminate MOG and undesirable fruit.
  • Automatic sorting tables require significantly fewer workers to operate than traditional sorting tables.
  • Some winemakers say the automatic models require a lot of adjustment to continue running efficiently.

It's not news that winemakers are adopting sorting tables to remove raisins, shot berries, jacks and other unwanted matter before fermentation. There's little need to explain to winemakers the value of fermenting clean fruit, and Tim Patterson covered the subject of sorting with manual tables a couple of months ago in Wines & Vines ("Gentler is Better," November 2008). More and more high-end wineries make the sorting process a necessary part of their regimen. But some also have been discouraged by the need to hire or assign a dozen or more people to this tedious task.

Automatic sorters can largely eliminate that demand, though they do require operators for supervision, and most winemakers agree that it takes a bit of learning to operate them effectively.

Winds of change

Three years ago, French equipment maker Vaucher-Beguet introduced its Mistral automatic sorter, which largely eliminates the need for humans to pick out defective material. Since then, many wineries have installed and are using the equipment, most with great satisfaction. They include a number of small units of Ste. Michelle, Kendall-Jackson and Diageo, as well as numerous highly regarded independent boutique wineries.

The Vaucher-Beguet line spans the Mistral 60, which handles 2 to 3 tons per hour, to the dual Sirocco, which processes 12 to 20 tons per hour. The various models are sold in North America by Scott Laboratories in Petaluma, Calif.

"It's received a phenomenal response," says Bruce Edwards at Scott Laboratories. "People bought it by word-of-mouth reputation without even seeing it in action." Edwards admits that response has come even though the machines aren't cheap, with prices ranging from $27,000 to $300,000.

He adds, "They may buy it to save money (in labor), but the real value is in improving wine quality. It does what people can't."

At this point, it's used at smaller and medium-size wineries, since it can't handle the requirements of huge wineries, which may process 50 tons per hour.

Not surprisingly, given model names inspired by strong Mediterranean winds, the Vaucher-Beguet Mistral and its larger brother the Sirocco use the force of air currents to separate the good grapes from material other than grapes (MOG) and defective berries. The destemmed grapes form a single layer on a vibrating table, then are separated a bit and fall off this table where a stream of air (an air blade) blows away light debris. It has to be readjusted for different varietals--even grapes from different locations, according to some winemakers--but is reportedly very effective in delivering clean berries for fermentation.

The company claims to automatically eliminate not only the bulky waste--large parts of stems, petioles and leaves removed by manual sorting--but also small items such as pieces of stems, seeds, shot berries and verjuice, as well as undesirable berries that are Botrytised, raisined or rotten.

Putting it to work

Diageo's Provenance Winery in Rutherford, Calif., got its large Mistral 140 in 2007. Winemaker Chris Cooney installed it to begin sorting grapes. Previously, the winery had a conventional setup: screw augur to the destemmer to the must pump. At that time, it installed the Mistral, and now the sequence is: cluster sorting to the destemmer to the Mistral automatic sorter. All red grapes fermented by the winery go through the system now.

"It required a lot of attention in 2007," Cooney admits, but in 2008 things went smoothly because they understood the equipment. "It does take a lot of work up front," he says.

As an experiment, Cooney collected the material rejected by the Mistral sorter and fermented it. "There is some waste," he says. "We definitely didn't want that in our wine." At Provenance, the shot berries are largely removed during cluster sorting, so the Mistral sorter doesn't have to do quite as much work, but Cooney says it does a good job of removing raisins and jacks.

He admits that Provenance picked the automatic system after an economic study, and seems quite satisfied. "It's not perfect, however. We're looking at a sorting table after it, but it would only take a couple of people, not 12 or 16."

He adds that many other winemakers have come by to check it out. "There's a lot of interest."

More users chime in

Sterling Vineyards is another unit of Diageo with a 140 Mistral system. Mike Westrick is the vice president of winemaking. He got the system this year after talking to sister companies Provenance and Beaulieu, which both have them. " This is a high-quality winery, and it makes sense. It's absolutely wonderful," he exclaims. Without it, a large number of people would be required.

As with other wineries, there was a learning curve. "We initially played around with it, but once we got it dialed in, it's worked fine." He says they've found that they have to adjust it for different varieties, ripeness and even quality, as well as for different vineyards.

Westrick finds it leaves a few jacks in the stream, and he's considering adding a post-sorting table to remove them, but he's not sure that a few jacks is a problem. "It's so clean, it may not be necessary."

Mistral systems are almost required equipment at Ste. Michelle's boutiques, including Northstar in Washington, Erath in Oregon and Stag's Leap Wine Cellars in Napa Valley. Stag's Leap winemaker Nicki Pruss says that during the first visit of new part-owner Piero Antinori, who also has a joint venture with Ste. Michelle at Col Solare, Antinori asked, "Where's the Vaucher-Beguet?" Since then, the machines have been added.

The Jackson empire also boasts a few of the Mistral sorters, including the model 100 at Stonestreet in Alexander Valley. "It's working hard and pretty well," says winemaker Graham Weerts. "You need a good destemmer, however." He intends to upgrade. "You can lose a lot of efficiency there."

Weerts has used the system "on and off" since 2005. Before, it only did cluster sorting. "This is better and more efficient," he says. "It gets 90% of the MOG, especially shot berries and stems." He sends all of the winery's high-end wines through the system and gets about 3.5-5 tons per hour throughput.

grape sorting
All fruit from Joseph Phelps Vineyards goes through the Sirocco automatic sorter (above).

Joseph Phelps Vineyards got a large Sirocco automatic sorter in 2007. Winemaker Ashley Hepworth says the winery previously didn't sort the berries. "It gets green berries, raisins and lots of jacks."

She says that they get about 3 to 5% waste and have to adjust the machine for every lot. "It takes a lot of adjusting."

All their fruit goes through the Sirocco sorter. Hepworth runs 8 tons per hour, sometimes slower, but says Phelps plans to get a better destemmer to speed things up. "That's the limiting factor. Some days, the process takes a long time," she admits.

She also tried the machine with mechanically harvested grapes as an experiment but found, "It was a little too juicy."

In Virginia, Abingdon Vineyard and Winery uses the smallest Mistral, the model 60. Bob Carlson got it last summer to remove stems after destemming red wine, but he hasn't been completely satisfied with the machine. "Certainly it helps, but it's not perfect. It's not very automated," he complains. "It takes four people to use it."

Carlson crushes vinifera, native and hybrid grapes including Cabernet Franc, Chambourcin and Norton. The berries differ a bit in size. "It needs a lot of adjustment," he says.

Not quite as sophisticated as the Mistral is Le Trieur from P&L Specialties in Santa Rosa, Calif. The U.S.-produced sorter removes undesirable material before the destemmed grapes get to the secondary sorting table. It was introduced in 2006. Le Trieur is mounted underneath or downstream from the destemmer and allows unripe shot berries, jacks, raisins and MOG to pass through a wire screen. Its gentle shaking motion then allows the whole, ripe berries to easily pass onward. This technology dramatically reduces the labor required for post-destemmer sorting.

Criveller Group also introduced a new automatic jack removal machine that can process 6 to 8 tons per hour. Produced by ENOVENETA Tecnologie Enologiche in Padua, Italy, the sorter has been used in Europe for two years, but launched in North America in 2008. It includes an elevated destemmer paired with a TSA automatic sorting table, with a separate crushing roller unit below that can be used if desired. It's designed for sorting after the destemmer to remove jacks and leaf stems and works with machine-picked and handpicked fruit. Berries fall though the grid to the crushing rollers or collection bin, while the jacks and stems fall into a separate bin. It costs approximately $30,000.

Custom-made automatic sorters

In addition to the Mistral sorters, Burgstahler Machine Works in St. Helena has delivered a few custom automatic sorters to California wineries as well. Its sorter customers in California include Darioush in Napa Valley, and Dumol and Littorai in the Russian River Valley.

Steve Devitt, the winemaker at Darioush, says, "I'm very pleased with the Burgstahler system." It's more than an automatic sorter, because it also includes a Delta destemmer. According to Devitt, grapes are fed and metered into the destemmer, then are shaken at different speeds into large mesh screens that separate undesirable material and juice. Air blows other debris away. He says the company specifies 4 tons per hour throughput.

Devitt processes about half of his red grapes through this system, and half through a system cobbled together 10 years ago, depending on workload. "If we have a lot of shot berries, we use this one. It does a very good job of removing them." He adds that the system is very well built using quality components.

Like most of these wineries, Devitt doesn't use it for whites, where he presses whole clusters.

Wayne Burgstahler has been making custom wine equipment for about a decade. He's developed a number of building block designs, which he can combine as customers desire. He claims they're pretty robust, admitting that he doesn't want to work on them after they're delivered. The company is fairly small and only takes on a few projects per year. Reach Burgstahler Machine Works at (707) 967-0553.

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