Soda is now considered a "lock cart item" for Intl?
 

So I know that liquor, beer, wine, etc is all in the locked carts for international flights departing the US but now Coca Cola products are locked cart items now too? (specifically US to Canada)

I think my last TPAC flight I asked for Diet Coke at pre departure and was given one but cant remember for sure

This reminds me when I got on a JFK-TLV flight, sitting in Biz, and asked the FA for a "very special rum & Coke". She told me that she can't give it to me until after take off.

I told her that she can if she makes it according to my directions: "Diet Coke, no ice, no lemon, and no rum -- stirred, not shaken". :D

I mean IF its true and soda is now a locked cart item DL is really penny pinching. I can understand not wanting to pay taxes on liquor because that can get expensive but I mean how much tax can be really charged on soda?

That feels ridiculous. I am not a huge soda drinker, but sometimes, after a week or two abroad, there's an inherent satisfaction in a Coke/Diet Coke with obnoxiously American amounts of ice. A crappy mimosa does not serve the same purpose.

Could it be related to sugary drink controls at the departure airport (or rather the city where the airport is located)?

Specifically - there isn't an excise tax here in Canada on soda (pop) particularly from the US (NAFTA, and whatever you want to call the next version of it). Possibly, and only possibly, they've issued an edict from the CRA (the IRS equivalent) that says you have to pay HST on consumed beverages on the ground. That HST would be recoverable as a business expense though (Delta would simply have to claim it on their HST return as an input tax credit). That suggests perhaps that they just don't know how to account for it or don't want to do the additional paperwork. That seems like something they could negotiate if they want to. Further, I have received PDB departing Canada on United, Air Canada and American (I do not fly Delta often - they are great but don't go where I need to quite as conveniently) . That doesn't explain your trip TO Canada though - that makes no sense. I think the flight attendant was tired that day.

Is this because of the "soda tax" that is being imposed on sugary soft drinks in PHL, NYC, etc.? Surely this cannot be more than any other excise tax charged on alcohol, even the cheap rotgut served on the ground.

Were you on a regional jet? It would be surprising to me if soda were a locked cart items, but it would be less surprising if you had regional jet FA who made up their own rules, as the latter is quite common.

If this was a smaller aircraft, it is entirely possible that the cart containing the bonded liquor also contains other items. Those items are effectively locked up too until after departure. On a larger aircraft or longer flight, the bar cart likely contains only alcohol and it is separately catered. This has zippo to do with cost.

I doubt that any of the bonded caterers deal with local soda tax issues.

I think the FA just did not want to open more things pre-departure and made this up.

I had this happen on an AMS-ATL flight a week or so ago. My initial request for a Diet Coke was denied because the cart was locked but some how the Purser helped the FA make it happen.

I've gotten this couple times. Normally I wait to purser comes by and ask "when did this change?" They then say it hasn't, and go get a can. FA from earlier comes by and apologizes claiming they didn't know better.