This doesn't strike me as very logical. 32 baby glasses of champagne cost, at worst, about CAD 150. Total annual cost no more than 55K CAD. Since half the people in J will usually consume mineral water pre-take off, anyway, the cost consequence is not significant. (Especially when they are stocking champagne on board anyway).

I think the explanation is far more likely that the Swiss are imposing punitive duties on opening bottles on the ground.

In order to keep the bar stock exempt from duty and excise taxes, the seals can't come off until the aircraft is off the ground, and the seals have to go back on before landing.

That means that for pre-departure drinks the airline has to either buy it locally (duty and tax paid) or else they have to pay excise and duty on the stock that they have brought in and intend to serve while on the ground.

For stations like LHR and CDG where there is an MLL, it is easy. The airline has to stock that bar anyway, so they just source the extra cases they need. For FRA, they might have a deal with LH on catering procurement (or else they send over the product they have sourced elsewhere in the Common Market).

But ZRH is not an alliance hub, and it is not in the Common Market, which probably makes the logistics more difficult.