Is it possible to use a 6 gallon glass carboy for a 5 gallon kit to bulk age? There would be quite a bit of head space...what if I added a like wine to eliminate the head space? The reason I ask is, I have read reviews on some 6 g kits where people recommend to make as 5 g to improve the taste. I'd like to try it but do not have any 5 g carboys. Any advice is welcome. Thank you!