John Kane has one of the greatest thankless jobs in California.

Kane, 35, is head winemaker for Rosenblum Cellars, which is now owned by global spirits/wine giant Diageo. He started at Rosenblum in 2001 as an intern when it was a very different place.

The Rosenblum brand -- a carefully chosen word -- has gotten little love from the wine press (including me) since Diageo bought it two years ago.

"Rosenblum" used to be a person: veterinarian-turned-winemaker Kent Rosenblum, famous for making 50 different single-vineyard red wines each year.

"Kent's a visionary who was 70 years ahead of his time," Kane said. "He was making old-vine Zinfandel when everybody was drinking white Zin. Then, when red Zinfandel became big, he had long-term contracts."

And "Rosenblum" used to be a winery: a popular spot in Alameda where neighbors could drop by and taste after work.

Kent Rosenblum is gone, having started a new winery; he doesn't publicly speak badly of his namesake winery, but he's not out promoting it either.

And Diageo closed the Rosenblum winery, leaving just the tasting room. The entire cellar crew was laid off.

"There were some positions offered, but people were family-bound," Kane said. "It was sad. It was hard. There was a lot of rapport -- barbecues, A's games. You got to know their kids, their wives. It turns into a family. You're building a lot of camaraderie. You ask somebody to crush all night because you're backed up and he just smiles."

Rosenblum wines are now made outside of Beaulieu Vineyards by the BV cellar crew. Kane said they average 18 years of experience at BV, but BV is a very different, more traditional kind of Napa Valley winery.

"I had a work order to dump some Viognier into Syrah," Kane said. "They didn't want to do it. They thought they would get in trouble, putting white grapes into red wine."

Want some more gloom and doom? K-Mart bought one of Rosenblum's best grape sources, Carla's Vineyard in Contra Costa County.

"K-Mart wanted to buy the whole vineyard but we had a contract, so they only bought half to build a parking lot," Kane said.

So why is this man smiling, seemingly all the time?

Because even after the company sale, the layoffs and the relocation, he's still making about 60 different wines, although it doesn't seem that way because wines under 1000 cases are now tasting-room only. Still, Kane has maintained most of the great vineyard sources that Kent Rosenblum found.

"When you do a bunch of vineyard designates, making sure they don't taste the same is a priority," Kane said.

Kane became Rosenblum's assistant winemaker in 2005 when Jeff Cohn left to start JC Cellars. "I didn't wait for the appointment," Kane said. "I just assumed the role and Kent was happy with it." He was 30 years old.

Kane inherited a style of winemaking, started by Kent and doubled down by Cohn: big, ripe, rich wines. It's not necessarily his own preference.

"I drink a lot of French wines and I like that dirtiness. That meatiness. That gamey quality," Kane says.

But he's not turning Rosenblum wines into something more delicate. Most of the wines we tasted together are labeled at over 15% alcohol, and while they did have complexity, they also had plenty of ripe fruit.

"I'd rather have 5% overripeness than 5% underripeness," Kane said. "Pyrazines and bell pepper, they don't go away. Our wines are targeted at millenials. They're young wines, they're vibrant and they're ready to go."

However, Kane makes the entry-level Vintners Cuvee Zinfandel in a much lighter style, with just 13.5% alcohol. He says he enjoys walking around stores incognito and listening to people talk about wines they're considering buying.

"Overachieving is the opposite of what you want at $10," Kane said. "People buying wine at that level use words like 'smooth' to describe them. I need to make sure these wines give that."

Kane also likes talking to buyers of $10 wines because it reminds him that, corporate buyout or not, he still has a job that he loves.

"I was talking to somebody yesterday who was pissed off about something in Paso (Robles) and I said, don't forget we have the best job in the world," Kane said.