Thanks for the response Ken.

Fortunately when I got home today and checked on it again, it was
fermenting nicely. The must is noticably higher than it was before and
while I can't see bubbles or froth on top of the must, when I punch
the cap the liquid underneath is nice and frothy.

To your point about the smell, it definately smelled like it was
fermenting, even before today so perhaps it was just working slowly
due to the cooler weather. Today was a much warmer day and it seems to
have jump started things.

My only fear now is that the must was initially left for 24 hours or
so without enough fermentation occuring to form a CO2 protective
barrier. As I understand it, if the must was exposed to oxygen for
this amount of time with no fermentation occuring, it could spoil
things? Can anyone confirm this?

Thanks again.

D