Pressing Matters

How important are presses to a winery? For some, it may be the most prized of their possessions. "There is a small winery in France that has one of our presses," said Karl Pfeiffer, "the house is very old and everything is very dark. But the press--that is another story. The wife is out there every day, lovingly polishing it so it shines. The kitchen is a bit of a mess and the toilet looks like it hasn't been scrubbed in 250 years--but the press, there is never a mark on it." While such devotion may be extraordinary, the press can be a very important asset to a winemaker.

Karl Pfeiffer is director of sales for Sutter AG, which is handled in the U.S. by Juvenal. The grapes can go in fresh or pre-fermented and take about 2.5 hours to process, depending on the size of the load. Sutter has been available in the U.S. for only the last three to four years and, according to Pfeiffer, is installed in about 9% of U.S. wineries. In Europe, Sutter holds about 85 to 90% of the market, per Pfeiffer. The presses are pneumatic and treat the juice more gently, extracting less tannin for a more balanced flavor. Their drum presses range in size to handle loads from 2.2 tons to 55 tons.

In contrast to all that shiny polished metal is the Marzola basket press offered by ConeTech. The basket press is popular with wineries that are open to the public because of the more traditional look that consumers expect. However, it comes with very modern features. The press is hydraulic with an electric engine. The plates are stainless steel with the bottom plate slanted to allow for maximum drainage. Basket walls are constructed of waterproofed wooden slats joined by stainless steel rings and they can be switched out, allowing for continual filling and pressing. The computerized control panel can be programmed in various speeds and pressure and is detachable from the press to make cleaning easier.

Also offered by Marzola is the progressive draining press. This is a continuous pressing system which is useful in big wineries that need to press large quantities of grapes in a short time. It processes close to 50 tons per hour. It is top-loaded into a chamber with an auger-type screw that separates juice from solids while moving the solids out the opposite end. And yes, Marzola does offer pneumatic presses as well.

With the exception of Marzola, most of the presses offered at the Unified Wine & Grape Symposium in Sacramento, Calif. last January, were pneumatic tank presses, which can operate at low pressure allowing for better control for extracting juice. Technology has also enabled operators to free themselves from the presses during much of the cycle. Most popular and almost standard features are a CIP (clean-in-process), which makes for faster cleaning and flushing of the presses and a PLC (Programmable Logic Controller), which allows operators to run a set program for the load.

Valley Pipe & Supply has several models of Defranceschi presses in both closed and open drums. The presses are constructed completely in stainless steel. Movable parts, such as gears, are enclosed, reducing safety hazards. The ends of the tanks are rounded, allowing for more membrane contact. The insides of the tanks are polished to a mirror-finish to help prevent adherence of pomace and other materials and to make the tanks easy to clean.

The Enoveneta press sold through Criveller has a fully automatic PLC system that can run any of the five preset programs as well as a customized program. If, for any reason, the PLC should fail, the system can be switched over for manual operation. The baffling system inside the tank helps break up the grape skins as well as channel end product out the doors for easy removal.

Rick White of fp Packaging handles Diemme presses. Because of customer requests, these presses feature the Alan Bradley based control system, a highly-regarded system in the American market. It is easy to service and parts are readily available in the U.S. There is no minimum load for the presses, regardless of the size; 500 pound of grapes can be pressed in the largest press without damaging the membrane. Diemme also offers two smaller presses, the 2300 and 2400 as either open or closed tank.

Pera markets a unique double-jacketed press. It features balloon jacketing around the closed tank in which glycol is circulated for greater temperature control. This feature is also popular in regions where nighttime temperatures don't drop much because the warm picked fruit can be quickly cooled down in the press.

Scott Laboratories sells and services Willmes presses. Rather than a traditional flow meter based technology, it features the UCE Juice Tracking system which uses decreases in pressure of the membrane to measure juice outflow. The press automatically responds to maximize yield relative to total press time.

Microchips are an important feature in many presses. Taking the PLC one step further, Vaslin-Bucher's offers the Bucher XP [LESS THAN LESS THAN]ORTAL[GREATER THAN GREATER THAN] or Intelligent program. The operator can run the press in manual, semi-automatic or the ORTAL mode. The operator sets parameters into the computer based on size and load of grapes. By measuring extracted juice through a flow meter, ORTAL will make "decisions" based on those parameters whether to continue or make adjustments, including shifting the load, for maximum extraction.

Matt Eiser of Euro-Machines doesn't buy into the assumption that technology is always an improvement. The company's Euro-Press is available with either a digital display or with toggle switches. "We have customers who don't like the digital systems. They would rather control the press manually so we give them that option." The company has been building the open membrane press since 1981 and continues to offer them as well as the newer tank presses. Both styles are completely stainless steel with double sliding doors that are standard rather than an option. They are available in either style: open or tank. The largest press can go up to 1,500 liters and has possibly the largest juice drain to hold all the pressed juice. Euro-Machines is factory-owned so customers deal directly with the manufacturers.

The newest kid-on-the-block is Vintek from Australia. The press is a closed tank/membrane press with a computerized touch screen control panel that makes it almost possible for one to set it and forget it. The panel is hooked up to Vintek by modem, allowing the company to upgrade or customize information as well as troubleshoot most problems from the home base in Australia. The computer can also be connected a printer to produce reports from a single cycle to the complete history.

Todd Boorman of Boorman Vineyards in Murrieta, Calif. found Vintek on the Internet when he was sourcing supplies for his newly-established vineyard and was the first in the U.S. to give it a try with his 2000 harvest of Cabernet Sauvignon. He was very pleased with the results and plans to upgrade to the VT 3000 for the 2001 harvest, using it as both a press and a rotary fermenter.

Yes, a fermenter. The Vintek press is a dual-purpose machine and can ferment product in as little as four days as opposed to 10 days in an open fermenter. Punch-down is not necessary; the tank is sealed and gently moves the juice, keeping the cap intact. It has a self-cleaning juice screen and is designed to be efficient for low pressure pressing for extended periods without blockage.

COPYRIGHT 2001 Hiaring Company
COPYRIGHT 2001 Gale Group