The chief viticultural aspect of making botrytized wines is the number of passages or tries through the vineyard which may have to be made in order to pick grapes only at the optimum point of botrytis infection, because noble rot is so crucial to quality. See sauternes for a description of the likely routine there. In a year as difficult as 1974 at Ch dโyquem (admittedly the most conscientious Sauternes estate), 11 tries were made over a ten-week period. In 1990, on the other hand, noble rot spread rapidly and uniformly and the grapes were picked by early October. In some vintages the spread and quality of botrytis may be so patchy that some estates, for example Yquem, Rieussec, and Suduiraut in 2012, elect not make a grand vin. Hand picking of these varied but usually disgusting-looking grapes is essential, and the cost of labour is one important element in the price of botrytized wines.
