Effects of Botrytis cinerea infection on Champagne wine foaming properties

Qualitative effects of Botrytis cinerea infection were studied by comparing the foaming properties of Champagnes obtained from healthy grapes with tho se from grapes infected by B cinerea. This is of particular interest when i t is considered that the foaming properties of Champagne wines are importan t in terms of product attractiveness for the consumer. Experiments using ar tificial viewing equipment clearly showed the dramatic effects on Champagne foam characteristics when grape berries were highly infected. The speed at which liquid separated from the foam (expressed as liquid height Ls) in th e glass depended largely on the level of infection for Chardonnary and Pino t noir wines (+ 26S% for Chardonnary wines at 40% infection and + 627% for Pinot noir wines at 20% infection). B cinerea infection reduced the time (L r) at which liquid first appeared in the glass; for Pinot noir wines an inf ection level of 20% caused very rapid drainage. The time of pouring (PT, ie the time to fill the glass under controlled conditions) also diminished co nsiderably at an infection level of 20% for both Pinot noir and Pinot meuni er wines (- 74 and - 58% respectively). Mouldiness considerably altered the foam height observed 80 s (H-80) after the start of pouring (-83% for Pino t noir and -89% for Pinot meunier at 20% infection). Champagne foamability was also quantified using a sparging technique to standardise effervescence . Foamability suffered considerably (-60 to -65%) when the B cinerea infect ion level was 20% as compared to control Champagnes. All wines studied had low and very similar protein contents. Differences in the concentrations of these compounds, which are generally implicated in the formation of foam i n sparkling wines, could not explain the differences in Champagne foaming p roperties observed here. (C) 2001 Society of Chemical Industry.