I seem recall many years ago, rumours of French crews on UTA (and possibly other French airlines) that would imbibe at lunch on the flight deck with a small glass of wine. This was a very French thing to do and by all accounts the amount of wine was of so small to be inconsequential but the tres Francois custom of having wine with food was upheld. I cannot verify this of course but it seemed credible at the time and we are talking the 80's here.