Depends how bad it is... If it's not very bad, I wouldn't worry too much, and I would never throw something out unless you're absolutely sure that it's knackered - i.e. you've tasted it and it's vile. Never ditch something just on suspicion!
Thats what I was thinking, its due to be racked this weekend anyway so I may throw a couple of camden tablets in. The white layer is def only surface so should be easy to remove without disturbing it too much..
Thanks for the advice
Gem
ps Can you tell I'm a newbie to the whole wine making malarky? :)
If you're racking at any time (and you don't object to Campden tablets on principle), then it's always wise to use one (or, as you say, two in the case of possible infection). Your white scum could actually be yeast rather than mould or bacteria. Smell it - if it doesn't make you go green, it's saveable.
What recipe did you use?
Mike
The secret of life is to aim below the head (With thanks to MMM)