Napa’s Portocork protects health, reputation of wine corks

Natural cork regains its dominance after addressing “taint” issues.|

Portocork America already controls the North American market for producing natural cork stoppers, but not all of them are being sold to vintners. A growing number are finding their way into beer and hard spirits bottles.

It’s just the latest development in an industry that has seen its share of change in the past few decades. First there was a growing awareness of TCA, the chemical compound sometimes carried in natural cork that can turn a bottle of delicious wine into something undrinkable.

Then screw-tops, plastics and other alternative stoppers were introduced to combat the problem, creating aggressive competition in the growing industry.

Napa-based Portocork America has weathered the storm by staying the course, responding with a 15-year focus on quality control that has helped it become the leading natural cork producer in North America, with an estimated 35 percent market share. About 1.5 million corks are produced each day by 40 employees at the company’s 50,000-square-foot facility in Napa.

The quality control division employs eight and is managed by Isabelle Sodini, a former research associate at Cal Poly San Luis Obispo.

“We test the cork immediately after it comes in raw from Portugal, by soaking it in wine and sending a wine solution to ETS lab in St. Helena to be analyzed,” said President Dustin Mowe, 36 .

“We then put the cork into our inventory, receive orders from customers to brand them with winery logos (using) fire, ink or laser printing, then add humidity to make them more elastic.

“Finally, we treat them with paraffin and a light spray of silicon before sending them out to 1,300 customers in North America.”

Among Portocork’s Napa and Sonoma customers are Robert Mondavi, Radio Coteau, Shafer Vineyards, Rafanelli Winery, Chappellet Winery, Arista Vineyards, Araujo Estate, Ravenswood Winery, Cakebread Cellars, Gary Farrell Vineyards, Pahlmeyer Vineyards, Simi Winery, Screaming Eagle, Clos Du Bois Winery, Spottswoode Winery, St. Francis Winery and Alexander Valley Vineyards.

Founded in the late 1970s in Porto, Portugal, the company opened a Bay Area branch in 1983, then moved production to Napa in the late 1980s. The Napa operation expanded to its current location in 1996, and Mowe became its president in 2006.

Protecting the health and reputation of the premium wine industry has become its primary goal.

Alternative stoppers were introduced in 1992 in response to “a lot of bad cork that was put into the market,” Mowe said. “The cork industry had blinders on because it was not forced to improve. It took us until 2000.”

As the quality of natural cork quality has improved, so have the prices. They’ve risen about 40 percent over the past 20 years.

For comparison’s sake, prices now range from 6 cents to more than $3 per cork, depending on the visual quality and length of the cork, while plastic stoppers average 3 to 4 cents each and screw tops average 10 cents (which includes the capsule).

Plastic corks are going away, said Mowe, accounting for only about 12 percent of today’s wine stoppers and used primarily by one producer, Gallo. Another 18 percent are screw tops, used mainly for white wines.

Natural cork continues to claim the lion’s share of the wine market, at 70 percent, because of its ability to its ability to seal the bottle while allowing in oxygen to help the wine develop.

As the wine world has come to understand the ways that top-quality cork is selected, manufactured and tested, said Mowe, Portocork America’s sales have grown steadily. In 2014 they climbed 17 percent, with more growth anticipated in 2015.

Competition is still fierce, especially in the North Bay.

“We have one competitor, Amorim, that does a lot of volume as well but really focuses on the value wines,” Mowe said. “We are still larger. After that there are a lot of very small companies - Laffite, Cork Supply USA, MA Silva, Scott Labs.

“We differentiate mostly because we only do natural cork and consider ourselves a specialist, while many of these competitors are diversified into other product offerings. We also partner with wineries and offer technical solutions. We have Dr. Sodini managing our quality department, and she is very active with customers.”

Mowe said he welcomes the quality-control challenge posed by top North American vintners who insist on having the best natural cork.

“Wine producers who demand top-quality cork such as Chateau Ste. Michelle make me a better cork producer,” he said. “They force us to have full traceability, full documentation and food safety certifications. They make me turn out a better product.”

The fast growing new beer and spirits market will no doubt bring equal - if different - challenges.

“We have about 100 distillery clients and 50 brewery customers all over the U.S., and it’s growing tremendously,” said Mowe.

With spring around the corner, Portocork’s busy season is about to begin.

“We have a huge run-up of business from February to August,” said Mowe, with white wines generally bottled in the spring, followed by red wines in the summer.

Contact Napa Valley Towns Correspondent Doug Ernst at

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