Processing equipment

Wines & Vines, Oct, 1999 by Larry Walker

One way to think about it

Wine processing is the nuts and bolts of winemaking. It isn't glamorous and you don't have wineries holding consumer seminars to talk about their stainless steel tanks or the latest wrinkle in a rotary press. Leave that to the barrel people.

But processing the raw material from crush pad to barrel or bottle obviously plays a key role in wine style, flavor and character.

When Don Van Staaveren arrived at Codorniu Napa (now called Artesa) three years ago, he was faced with the unusual problem of converting an overbuilt sparkling wine facility to still wine production.

"The first thing we did was look at the overall configuration of the equipment. We had to think of tank sizes and shapes, pumps, stemmer/crushers, hoppers, virtually every piece of wine processing machinery," Van Staaveren said. "We evaluated what was there with the goal of premium still and premium sparkling wine production," he added.

"We basically went piece by piece, based on experience and based on looking at what newer wineries were doing and how equipment was being adapted to techniques."

His first major decision was to get rid of an unusual belt press which the Catalan owners of Artesa had installed for champagne production.

"The belt press generated a lot of solids and was contrary to the trend toward the whole cluster approach being used by premium sparking winemakers and by premium white still wine producers," he said. "It wasn't that difficult a decision."

Van Staaveren's approach emphasizes flexibility, so his options include whole cluster, direct to press, de-stem only, de-stem and crush, and use of the must chiller and skin contact. All white varietals, about half of the Bordeaux red varieties and Pinot noir are brought to the winery in half-ton bins, with the balance delivered in Valley system two-ton bins. He also increased the screw conveyor diameter from 12 to 18 inches, doubling its size and operating it at half-speed and changed the bottom configuration so the screw fits snugly into the channel. These changes provide a more positive delivery and prevents fruit from piling up or bridging over the screw conveyor.

The Waukesha 320 positive displacement must pump operates at about 600 rpm, or one-third of maximum speed, with a 6-inch cavity feeding into a 4-inch line. The Vaslin-Delta E-6 destemmer is operated as slowly as possible to obtain as many whole berries as possible. Although it is designed to run at 60 tons per hour, Van Staaveren operates it at 20 for the most part and even at full production doesn't expect to exceed 40 tons per hour.

The must chiller reduces must temperature 20 degrees F for slow phenolic extraction with whites and for cold-soaking Pinot noir. Van Staaveren can bypass the chiller and load directly into either press by axial feed or load the dejuicing tanks. One short line feeds the end of each press to minimize pumping distance. The press is filled doors up and not tumbled so that berries are not broken.

Dejuicing tanks are used for skin contact with white varieties and for fermenting reds. The 12-ton tanks are bottom filled at low pressure, about ten pounds, to decrease mechanical damage. All bottom valves are 4-inch for more efficient draining.

For red wine, fermentations in dejuicing tanks was born out of necessity, but has proven to be desirable. The screens strain juice from the pomace during the pump-over. The cap is wet by sprinkler and isn't broken up; this produces fruitier reds without the extraction of other methods. They are brighter, fresher wines which offer a valuable component for blends.

Open-top fermenters, made by Westec, all have at least a 1:1 ratio of height to diameter, plus cap space. Four two-ton portable redwood tanks are used for experimental lots. There are four six-ton fermenters.measuring 6 feet by 6 feet at fermentation level, five 10-ton fermenters measuring 6 feet by 7 feet 5 inches and eight 13 ton fermenters at 6 feet by 8 feet. The tops and bottoms are at equal heights to accommodate the pneumatic punch-down from above and the drain bins below. Punch-down depends on the variety and level of extraction desired. It averages four times daily.

The open-top tanks have floating lids with inflatable rubber gaskets so that the lid can be positioned right on top of the must, juice or wine.

The closed-top fermenters, built by Liquid Assets and Quality Stainless Tanks, are intended primarily for Cabernet Sauvignon as well as a little Pinot noir, Zinfandel and Tempranillo.

Given Van Staaveren's emphasis on small lots, there are 10-1,000 gallon and 10-2,000 gallon fermentation and storage tanks, produced by Santa Rosa Stainless Steel and Liquid Assets.

"Part of my philosophy is to keep vineyard blocks separate and make wine in small lots, which means 5 tons to 15 tons. We sized the tanks accordingly. There were some practical guidelines. For instance, a truck load of grapes runs 20 to 24 tons. That fits nicely into two 15-ton fermenters," he said.

Van Staaveren started with an 8,000-liter Diemme AR80 press for white wine, which holds about six tons of whole cluster fruit. That worked well for both sparkling and still wine, especially since he was taking small lots of fruit (often for experimental purposes) from estate vineyards. Also, since a 15-ton fermenter drains into an 8,000 liter press, both red and white wine was covered by the same equipment. For the next vintage, as production increased, the winery bought a 15,000 liter Willmes TP1e5 press, which takes a little over 12 tons or half-a-truck-load of grapes, for white wines.