LOS ANGELES (AFP) - Peter Mondavi, a trailblazer in developing Napa Valley's wine industry and owner of Charles Krug Winery, has died at 101, his family said on Monday.

He died at his home in St Helena, California, on Saturday, a family statement said.

He was the brother of Robert Mondavi, founder of a wine empire full of innovation and marketing savvy that inspired the documentary Mondovino in 2004.

Their modest family - Italian immigrant parents who had not worked in the industry - moved from Minnesota to California in the 1940s, after their father, Cesare, started visiting California to bring, and later ship, wine grapes to the colder central United States.

Back then, Napa was known for fruit growing but inexpensive, poor quality wine.

Peter Mondavi, who worked with his father as a boy nailing grape crates shut, ultimately pioneered cold fermentation. He also began importing French oak barrels for aging wines, and was among the first to use vintage years on varietal wines.

In 1943, Cesare bought Charles Krug, now one of the oldest vintners in Napa Valley. In the 1960s, a disagreement between Peter and Robert led to the latter starting his own businesses.

Peter took over the reins of the family winery after his mother died in 1976.

California Governor Jerry Brown in 2011 honoured him, and the legacy of the Charles Krug Winery, with a proclamation on his contributions to the wine industry.