Originally Posted by
Howard Long
I happened to notice that they used half bottles of Pommery Louise on the ground at LHR, not sure if that is common, or extended to in-flight too. ISTR Champagne halves typically aren't quite made in the same way as larger sizes, but I can't say I noticed in this case.
They have to pay tax and duty on any alcohol they open on the ground, so I'd suspect (though someone more knowledgable can confirm/correct) that they did this to reduce the tax bill, and then had full bottles in the locker for in flight service (which is duty free).