Batter...that reminds me.
I add at least some sparkling instead of ordinary water to the mix for Yorkshire pudding, which is the only batter I make. Gives a lighter pudding. (Think I read the suggestion in a Gary Rhodes book).
Wonder whether it would make a difference to other batters? Suppose if you're using beer it's got a bit of fizz already.
PS Yes I know it's only a wimp metro-southerner like me who would want his Yorkshire Pud a bit lighter, just thought I'd mention it....