The weight would depend on a number of factors:
- How thick are the glass bottles (Sparkling wine is under pressure and has thicker bottles than still wine)?
- Is it a case of 6 or 12 bottles?
- Is it a cardboard or wood case?
A very rough estimate would be:
A normal size wine bottle is 750 ml (¾ Litre). Litre water weighs 1Kg, so 750 ml wine is approximately 750g.
Add the weight of the bottle makes about 1Kg per bottle
6 bottles = 6 Kg
Plus a cardboard case ~½ Kg
Total 6.5 Kg. This is a very rough guesstimate.