Rosenblum Cellars and Its Descendants

The Legacy of Generosity

By Derrick Schneider | Photos by Melissa Schneider

Rosenblum Cellars is an important force in California’s wine industry. It’s one of the famous “Three R’s,” the leaders of the Zinfandel pack (the others are Ridge and Ravenswood). Rosenblum looms above smaller Zin producers the way its facility, a former airplane hangar, looms over Alameda’s Main Street.

Behind it all is Kent Rosenblum, the brown-haired, mustachioed veterinarian who started the winery in 1978 after years of making wine at home. His medical background drew him to the scientific side of wine making, a passion he still pursues in the sizable on-site lab. His wines gained a following with the press and the public, and his winery grew steadily, moving from its Emeryville location to the Alameda hangar.

Ken Rosenblum and Jeff Cohn

Most people praise Rosenblum’s generosity, and it’s not uncommon for him to donate bottles to an art show or a local business’s grand opening. That, as much as the wines themselves, makes Rosenblum Zin a Bay Area favorite. The winery’s quarterly Open House attracts throngs of fans who fill the massive building to taste (though rarely spit) some of the 52 wines Rosenblum makes. The portfolio ranges from inexpensive blends to pricey single-vineyard bottles, from Zinfandel to Rhône varieties: Syrah and Viognier to name a couple.

These wines all share an intense fruit character. “It’s all about the fruit for me,” says Rosenblum. He asks farmers to leave the grapes on the vine as long as possible and his cellar techniques maximize that extracted fruit. But the overripe grapes hold more sugar, which generates high-alcohol wine during fermentation, which in turn makes the wines less food-friendly. Critics decry these monstrous alcohol levels—15 percent is common—even as the most influential reward them with high scores. Rosenblum acknowledges the complaints, but feels that the concentrated flavor makes up for the heavy weight. At any rate, big wines sell well, and Rosenblum’s visibility leads other wine makers down the same route.

Size and output are only two of the reasons for Rosenblum’s influence. It also comes via the wine makers who have spent time in the massive hangar as staff members or renters needing space and time on Rosenblum’s equipment. Rosenblum doesn’t think of himself as an “incubator”—a Silicon Valley term for a firm that houses newly minted startups—but his unique space lowered the bar for new wine makers entering the marketplace.  He had room to spare, and it’s not surprising that the former amateur wine maker encouraged other hobbyists to “turn pro” under his roof. Though he charged for the space, his advice and experience were free.

 “He’s like a walking encyclopedia of wine knowledge,” says Zoom Vineyards owner Jerry Martin. Continuing in his Texas drawl, Martin explains how other vintners have benefited from that knowledge. “I doubt any of the independents would be around today if it weren’t for him. He is generous beyond what anyone would imagine. He’s a prince of a fellow. He’d come by, taste our wines, and say, ‘You know, it needs a little something extra.’ Often, he would even suggest that the wine needed something from his own barrels, and he’d sell us some for a reasonable price.” Rosenblum’s partnerships with premier growers made this a welcome gesture.

Martin’s time at Rosenblum influences him today. “In some ways, we’re a lot alike. We both make high-alcohol wines with intense flavors.” Robert Parker, the influential wine critic, describes Martin’s wines as “hedonistic,” a popular Parkerism for his favorites. But Martin isn’t interested in mimicking Rosenblum’s portfolio: Where Rosenblum offers 52 labels, Martin offers just two-to-four high-end, single-vineyard Zinfandels.

Thomas Coyne, one of the best wine makers in the Livermore Valley (see Edible East Bay, Fall 2005) got his professional wine making start at the facility. Rosenblum had tasted Coyne’s homemade wine and had even secured grapes for him. When Rosenblum needed an assistant wine maker, he turned to Coyne. “Kent was just starting their program to grow into a large winery,” recalls the Livermore wine maker, “and he needed some people to help.” Coyne was a perfect choice. His long-time career at Clorox gave him the skill to manage industrial scales and his amateur wine making gave him insight into the process he supervised.

In 1989, Coyne asked if he could rent some space in the hangar for his own wines. Rosenblum was generous with advice and assistance for his protégé, as he would be for the small wine makers who followed in Coyne’s path. “I learned a lot from Kent. He’s a good wine maker, with an excellent palate.” Like Martin, Coyne left Rosenblum with a new awareness about the benefits of blending. “We’d have some nice Zin and Kent would say ‘We need a little something of this or that, maybe some Petit Sirah.’ It became a better wine. He had a good understanding of the principle.”

Also, like Martin, Coyne is quick to praise Rosenblum’s generosity. “One time, Kent had ordered some Cabernet Sauvignon and Merlot from Holbrook Mitchell,” explained Coyne. “I asked if I could buy the Cabernet Franc. Kent was fine with that—he didn’t have any interest in it—and I placed my order. But when the truck came in, it brought four tons instead of one.” Coyne panicked until Rosenblum stepped in. “Kent told me to go ahead and make the wine, and he’d buy the remainder off of me.” Neither knew how serendipitous that gesture would be: Rosenblum liked the wine so much he blended it with his Holbrook Mitchell wine, creating the Holbrook Mitchell Trio that continues to win prestigious awards today.

Michael and Anne Dashe

Not every former tenant considers Rosenblum a major influence. “We already had a pretty good idea of what we wanted to do,” says Michael Dashe of Dashe Cellars. He and his wife Anne make their well-balanced wine together based on their extensive experience: He worked in wineries around the world before his eight years as an assistant wine maker at Ridge, and she has an extensive wine making resumé along with an enology degree from the University of Bordeaux. The wines are delightful, offering integrated flavors that show thoughtful wine making and they suggest the potential to mature well in the bottle. They also differ from Rosenblum’s style in a number of ways.

For the Dashes, Rosenblum was a place to park rather than a place to learn. But even so, Dashe benefited from his time as a Rosenblum renter. “Kent would let us try samples from different coopers,” says Dashe, “so we could see which ones we liked.” Dashe also uses some of the bin fermentation that is a hallmark of the Rosenblum cellar, in which grapes are fermented in small tubs, several feet on a side and a few feet tall. It gives the juice more exposure to the skins and extracts more flavor. “I prefer fermenting in tank,” says Dashe, “But we use bin fermenting for our overflow. That was a technique I learned at Rosenblum.”

Kent Rosenblum influenced his tenants, but also gave them insight into their own preferences. “I like Kent’s Zin program,” says Coyne, “but his style is high alcohol and more extracted than I wanted to do. I wasn’t looking to be a Rosenblum clone. My style is towards lower alcohol and good fruit.”

Rosenblum’s current wine maker, Jeff Cohn, has kept the high alcohol in the wines he makes at JC Cellars, housed in the Dashes’ Oakland facility, but distinguishes this wine in other ways. “We’re a bit more terroir-driven,” says Cohn, referring to the French concept of a “sense of place” unique to wines from a particular site or region. I like a bit more new oak, I don’t filter, I don’t rack as much,” he says of his wine making style at JC. Still, the JC wines seem more similar to Rosenblum’s than different. His 2002 Ventana Vineyards Syrah is the most significant departure, offering less fruit than the wines he makes at Rosenblum, but still plenty of flavor.

Rosenblum continues to do well in the press—the 2003 Rosenblum Rockpile Road Vineyard Zinfandel was named one of Wine Spectator’s Top 100 Wines of 2005—and no doubt its wines will continue to seduce wine drinkers in new releases. But the era of “the independents” is coming to a natural close. The winery has expanded to the very edges of their large warehouse (“I never thought we’d fill it all,” says Rosenblum, shaking his head as we tour the facility), and the small wineries that sheltered in the hangar’s walls have been forced to seek out new spaces. But those wine makers remember what it meant to them to have a chance. Cohn has taken on an assistant wine maker at JC Cellars, and he uses Cohn’s space for his own wine making venture. Even if Rosenblum’s wing doesn’t directly cover small wine makers anymore, its shadow still does.


Derrick Schneider is a food and wine writer, wine educator, and computer programmer. He has written for The Art of Eating, The Wine News, and Wine Review Online, and he writes the “In the Kitchen” column for His wine classes are always popular and well-regarded. His food and wine blog, An Obsession With Food, has been praised in the mainstream press and it attracts several thousand regular readers each week. He lives in Oakland with his wife and two cats.

Melissa N. Schneider is a freelance photographer, custom woodworker, and jewelry maker based in Oakland.