> If you are in doubt about the ability of the screw cap to seal tightly,
> first fill the bottle with water, cap and let it stand upside down for
> 24 hours and see if it leaks. If no water cames out, it is sealed and
> air won't leak in>

You could also add some vinegar and baking sode to the bottle
and then cap it. A slight dip in some soapy water will quickly
show bubbles if there is a leak.

I've been considering using some whiskey bottles for wine for
some time now and think I will give it a try for the next carboy.

Don