Petrassi will effectively replace Justin Howard-Sneyd – who left Waitrose in February – on July 19, but in what will be an expanded role.
Beer and spirits are being added to Howard-Sneyd’s previous role as head of wine.
Petrassi will head the buying team for all drinks product areas and oversee Waitrose’s vineyard project at Leckford in Hampshire.
Petrassi, who became an MW in 2007, is currently a senior product development manager for wine at Tesco, and has previously worked for Waverley TBS and International Wine Services.
Suzanna Duke, Waitrose’s director of buying, said: “He brings with him a wealth of commercial experience, as well as a passion and enthusiasm for wine. Re-introducing a head of buying level is part of a larger restructure across all areas of buying, and is due to unprecedented levels of growth and increased complexity in the buying process.”