Kent Rosenblum, an iconic winemaker and passionate advocate of California Zinfandel, died unexpectedly Sept. 5. Rosenblum, an avid skier, underwent elective knee surgery in August, but complications followed. He returned home from a follow-up surgery last week and passed away in his sleep in the early hours of this morning. He was 74.

"I'm really going to miss his Sven and Ole jokes," said winemaker Joel Peterson, a friend of 30 years and founder of Ravenswood. The jokes about a wacky pair of Scandinavians, popular among native Minnesotans like Rosenblum, were his trademark, according to daughter Shauna Rosenblum. "He was supposed to write them down for me," she said with a laugh and a sigh.

Rosenblum was a veterinarian living in San Francisco's East Bay when he started making wine in his basement in 1972. "Kent always said that wine was a hobby that got out of hand," his brother Roger recalled.

By 1978, Rosenblum Cellars was ready to go commercial, but the first few years were a struggle. When Shauna was born in 1983, Kent said he would give the winery just one more vintage to succeed. As it happened, the Rosenblum Zinfandel Hendry Vineyard 1984 was a success, and in the following years the wines earned outstanding scores from Wine Spectator.

While most winemakers eyed locations in Napa or Sonoma at the time, Rosenblum Cellars settled into an old warehouse in Alameda, an island community and the site of a former Naval airbase off Oakland. It was among the first urban wineries in California to become a popular tourist destination.

Rosenblum made a range of wines, but Zinfandel was his first love. "Zinfandel and old vines were really the core of what he did," said Peterson. "He recognized California's historic vineyards, which was unique at the time." A champion of vineyard-designated Zinfandel, Rosenblum at times produced 20 to 30 different bottlings from across California in a single vintage.

He also helped inspire new generations of winemakers. "As one of the three R's [Rosenblum, Ridge and Ravenswood], his wines of the 1980s and early '90s helped fuel my passion for Zinfandel," said Mike Officer of Carlisle, one of today's top Zinfandel producers. "That led me to abandon my software career to specialize in making Zin."

While he was among the cultish R's, Rosenblum's style was distinctive and ripe. "He made wine that was very Kent Rosenblum," said Peterson. "I always thought Kent's winemaking verged on miraculous. The wines were uber-ripe and could have been a disaster, but he made them great."

In 2008, Rosenblum and his wife Kathy sold their winery to Diageo for $105 million, in a move that surprised some. "We didn't really have a plan to sell the winery," Kathy said. "But they came to us with too much money to say no."

That same year, Rosenblum founded Rock Wall Winery with Shauna. "Basically, Dad wasn't done making wine," she said. "I'm completely honored I was trained by the best."

Kent Rosenblum was born in Mason City, Iowa, July 29, 1944, but was raised in St. Paul, Minn. He met Kathy while attending the University of Minnesota. They were married in 1969, and the following year they moved to Alameda.

Rosenblum will be remembered for his humor and humanity as much as his wine, friends and family say. "Kent was a terrific human being, very kind and very generous," said Officer.

Rosenblum is survived by his wife, Kathy, daughters Shauna and Kristen, and granddaughter Skylar.

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