Peter Mondavi Sr., who, with his brother, Robert, made the Charles Krug winery an early leader in the Napa Valley’s rise as a great wine region before the two had a bitter falling out, died on Saturday at his home in St. Helena, Calif. He was 101.

His death was announced by the Charles Krug Winery, which he owned with members of his family.

In 1943, Peter and Robert Mondavi convinced their father, Cesare, a grape shipper, to buy a derelict vineyard and winery founded in 1861 by Charles Krug, a Prussian immigrant. The sale was completed for $75,000, and the brothers set about making quality wines that would stand apart from the cheap jug wines that defined California in the industry.

Peter Mondavi almost immediately began introducing ideas he had been experimenting with while studying oenology at the University of California, Berkeley, notably cold fermentation to produce crisp, fruity whites. The winery was one of the first to use new French oak casks for aging and to adopt the then-novel practice of vintage-dating its varietal wines. The Charles Krug Winery soon became known for its Vintage Selection cabernets, big, well-structured, elegant wines that achieved classic status.

Robert Mondavi, a charismatic marketer with grand designs for the winery, clashed repeatedly with his quieter, more conservative brother, who was in charge of technical production. Peter Mondavi acknowledged growing resentful of his older brother’s starring role and demanding ways.