Comstock Wines in Healdsburg, Calif., is one of Sonoma County’s newer wineries, having opened its doors just three years ago, in Au¬gust 2015. But Bob and Sandy Comstock had been selling grapes for well over a decade from their family vineyard near Geyserville, Calif., and it’s from that personal estate that the two began their winemaking venture.

Today, the couple owns a 20-acre vineyard along Dry Creek Road, which also includes a 21,000-square-foot facility, featuring a large tank room, multiple barrel rooms, a lab, cold room, crush pad and, of course, hospitality areas. Yet, despite all the state-of-the-art, mod¬ern equipment that adorns the winery permit¬ted to produce 35,000 cases a year, there sits in the corner a memory of simpler times.

Meet Bertha. She’s the Comstocks’ original press, an Enorossi Idropress basket press. She can press no more than 1 ton at a time and produces 70% less juice than the winery’s newer Puleo SF-50 open drain membrane press. Bertha’s more of an inside joke than a serious piece of winemaking equipment. Though she’s so-named because she was, in fact, the largest piece of winemaking equip¬ment the Comstocks had in their basement-turned-winery just 15 years ago, she’s now one of the smallest in their new facility and used only for a select few pressing jobs.

But talk to Comstock’s winemaker, Chris
Russi, and there’s still some love for the old girl. Russi said that of the 300 tons of grapes Comstock brings in, Bertha presses about 3. “We really only use her for a small percentage of experimental lots. For example, we may do 1 ton of Merlot completely whole cluster and then use the basket press,” he said. “You don’t really get the same efficiency as from the blad¬der press, but the quality is better.”

Russi said that in his previous winemaking position, he worked exclusively with a basket press from Carlsen & Associates for his pro¬duction of Zinfandel and Pinot Noir. It was a press he really enjoyed, calling it an old-school press with new-school technology. “I really loved the versatility and the readout display,” Russi said. “You could see exactly what the pressure inside was as opposed to relying completely on tasting.”

But besides Bertha, Comstock doesn’t have a basket press in regular use, instead relying on the Puleo Drain Press bladder press. “I’m one of those winemakers that has had access to a basket press and know what they can offer,” Russi said. So his solution, when he wants to get the quality of a basket press’s pressed juices but is pressing larger quantities than the 1 ton Bertha can handle, is to run the winery’s bladder press “like a basket press.”

“What I do with specific lots is I’ll do one press, hold it and repeat, maybe three times without tumbling in between presses,” Russi said. Working the bladder press “manually” and preventing the tumbling between press¬ing sequences inhibits the organoleptic mate¬rial from breaking up and producing a more phenolic and tannic wine. Russi said he uses this technique for some of his “bigger” variet¬ies and said it works particularly well with his Grenache.

Comstock may invest in a new basket press in the future. “Right now, we’re starting off very small, only making 6,000 to 7,000 cases a year,” Russi said. “Once we hit the 10,000 to 15,000 mark, we’ll probably get a basket press.” He has his eyes set on another Carlsen.

Small lot at Lauterbach
Not every 1-ton basket press is resigned to the corner of the winery. At Lauterbach Cellars in Windsor, Calif., it’s quite the opposite. When you pull up to Stu and Barb Lauterbach’s winery, the place looks more like a house than a traditional production facility — except for the Idropress basket press that sits in front of the building.

The 1-ton basket press is the very same Enorossi brand press Comstock has, but it is used on a regular basis at Lauterbach Cellars. “It’s very simple and easy to use,” said owner and winemaker Stu Lauterbach.

The Idropress has an interior elastic mem¬brane, or bladder, which inflates with water pressure up to about three bar. The press is controlled by turning water on through a valve with a pressurized gauge. “You turn the water on until you get to a certain amount of pressure, shut it off and let it sit,” Lauterbach said. It’s all done manually, and Lauterbach said there needs to be at least two people manning the press to rotate out the full bucket of press juices for an empty one until the pressing is completed. Each press cycle lasts about an hour or two.

The couple produces only 200 to 300 cases of wine annually, working exclusively with Syrah and Pinot Noir grapes from estate vineyards.

“After harvest we destem, and our destemmer fits on top of our T-bins,” Lauterbach said, explain¬ing that the T-bins are about 4 feet in length and height and about 3½ feet wide. “We fill the T-bins about eight-tenths of the way full to make room for fermentation, and that exact amount fits into the press,” he said.

The couple purchased the used Idropress in 2003 from neighboring winery Pax Mahle Wines, which made the original purchase just three years earlier. “It was just like new, but they’d already outgrown it,” said Lauterbach.

Lauterbach said the results are good, providing him with both the quantity and quality of pressed juices he needs to produce his boutique batches of wine. He warns that a press like this can fail: The bladder can break and leak, and it’s about $600 to replace the whole membrane.
Newer Idropresses are more frequently sold with a stainless steel basket, said Lauterbach. Though he said these may be faster to clean, he doesn’t find cleaning his wooden basket press all that difficult. “We just use a pressure washer with 180° F water and wash it down when we’re done. Before we use it again, we ozone sterilize.”

The “Ferrari of basket presses”
"This basket press is so incredibly gentle, the pressed juices almost taste like free-run," said Jesse Giacomelli, assistant winemaker at Zialena Winery in Geyserville, Calif., during an interview for Wines & Vines’ August technical spotlight. He’s pointing to the winery’s Bucher Vaslin JLB automated basket press. “It’s the Ferrari of basket presses.”

The Bucher Vaslin JLB basket press has been on the market since 2002, and the company’s sales and marketing director, Mea Leeman, says it is the first to be fully self-contained, running on a closed-loop hydraulic circuit, resulting in a compact, mobile press. The JLB comes in 5-, 12- and 20-hec¬toliter capacities with pressing cycles lasting between 45 and 60 minutes.

What makes the press “so incredibly gentle” is what Leeman calls the “respiration aspect.” Instead of pressing the pomace all at once at a continuous pressure or tumbling the pomace in between presses as in a bladder press, the JLB releases ten¬sion between successive pressing cycles, allowing the pomace to “breathe” or “bounce back.” This gives more room for the pressed juices to flow during the next pressure cycle without any un¬necessary added force.

While the general functionality of the press is consistent from year to year, Leeman said the one thing that’s always evolving is the JLB’s touch-screen PLC unit. The PLC system includes nine adjustable program options, which adjust pressure on pomace and pressure holding times.
“With the intuitive communication system, you can see where you are during any part of the press¬ing process,” said Leeman, explaining that the readout display provides real-time pressure up¬dates that can be viewed as either a number or a graph. “And you can get text message alerts when the set pressure has been reached,” she said.

At Quintessa Vineyards winery in St. Helena, Calif., the production facility is home to three basket presses — all of which are Bucher Vaslin JLB presses. Winemaker Rebekah Wineburg said Quintessa currently produces 10,000 cases annu¬ally of the Quintessa red blend. The winery also helps out with the red wine production of sister winery Faust. In all, Wineburg said, the winery presses about 1,000 tons of grapes per harvest, with about half of that coming from their estate vineyards and the other half coming from Faust.

“Multiple presses help with the multiple brands,” Wineburg said. “If you’re harvesting really fast, then logically you’ll be pressing very quickly.”

Quintessa uses two JLB 20 presses, purchased in 2003, which Wineburg said help her press a larger volume of grapes at a faster, continuous rate. But when she wants to press smaller lots, keeping them separate and exclusive to certain higher-tier wines, she uses the third, a JLB 12, which Quintessa acquired from Flowers Vineyards & Winery in Healdsburg, Calif., in 2017. Quintessa, Faust and Flowers are all owned by Huneeus Vintners.

“For production of Bordeaux varieties, I really like the basket press for ease of use and quality,” said Wineburg, explaining that JLB’s basket press can be placed directly under the pomace door or under an incline conveyor if the pomace door is too low. The pomace can then be shoveled directly into the basket. “It’s an efficient process as well as allows for delicate handling of the pomace.” An important component for Quintessa, which is home to 70 tanks.

Wineburg said she uses the PLC system to split her press cycles into three customized fractions: “The first is the lightest press, which actually has the highest lees; the second is the core of the press, which is the highest quality and volume of press; the third is the heavy press. … The second is the most useful for adding midpalate density to the final blend,” she said.

Wineburg said she simply started with the manufacturer’s recommended pressure settings and then adjusted until she found the press cycles that work for her wines’ profiles.
The JLB also includes two pressing cages, allow¬ing for continuous demolding and pressing. The cages have what Wineburg calls an ample reservoir. “It’s nice because it allows you to start the press or close the valve and switch tanks without pausing the press cycle or making a mess. It sounds simple, but I’ve had other presses overflow, causing an an¬noying mess and loss of wine,” she said.

The reservoir also allows Wineburg to see how much wine is coming out of the press, gauging the effectiveness of her press program.

Looking toward the future
Collopack Solutions in Napa, Calif., represents Italy-based Diemme Enologia, which is currently testing its Diemme QC620 continuous basket press. Already installed at wineries in South Africa, Italy, France and Romania, the press was set up at Scheid Family Wines in Greenfield, Calif., for a trial in October.

The Diemme QC620 is a horizontally mounted basket fed by a 20-bar peristaltic pump. Initial pres¬sure is built by the pump feeding pomace against a closed door. Once that pressure is built up and the cage filled, the door opens (expelling the dried cake) and the pressure continues to build up against the cake remaining in the cage, continuing the cycle. According to the technical sales representative for Collopack Solutions, Adam Bloom, the throughput is 15 tons to 45 tons per hour.

“A traditional basket press is typically seen as something that only high-quality red wine produc¬ers have the luxury of using,” Bloom said. “This press supplies the same quality as a traditional basket press with a higher throughput.”
Bloom said there’s been a significant amount of interest in the press here in the states, but before anyone actually invests, winemakers will want to see how it runs. So, during the month of October, Scheid ran the Diemme QC620 for its red wine program. Diemme representatives were on staff, and the team tested for yield, phenolics, color, sulfur, pH, rate of throughput and the humidity of the resulting cake.

“The reason we are working with Diemme and their new continuous press is to see if this equip¬ment will improve our overall quality and through¬put capacity for red grapes,” said Dave Nagengast, vice president of winemaking at Scheid Family Wines. He said the winery is currently using the Diemme 430 presses, which have produced great-quality wines for the winery. “But these presses are also used for white grapes, so there is competition for the use of these presses while we are busy bringing in both at the peak of harvest.”

Nagengast said that the Diemme QC620 is just “one of several options” for the Scheid winemaking team to increase their red-grape processing through¬put. “We will be running trials on all phases of the red-fruit processing to see what options it might offer us for improving both efficiency and quality.”