We did the same thing on the Hecla, we were stashing it in one of my compartments and bringing it out a bit at a time. The can man sussed us out when he did an inventory though and (all credit to him) got all the beer bosuns together and we agreed to stick a few extra pence on every tin we sold in the mess to make up the difference. The Joss would never have found out and it would have been a happy ending but.....
A rather simple S&S rating decided to complain to the SO that the price of beer had gone up too much!!!! Tool !
Anyway, after a few weeks of threats of the SIB coming onboard (yeah, really scary that was, not!), it all blew over. Oh how I miss those jolly japes, only allowed 3 tins and only at certain times, in fact feck it, I think I'll have one now for breakfast..... cos I can.