can a customer take an unopened sealed non-alcoholic beverage into a bar to be used as a mixer?!

Best Answer - Chosen by Voters

If they bar doesn't have that unopened sealed non-alcoholic beverage and it is required for your drink they should have no issue with it.

Some bars may say stuff about it but you can always talk your way in to it. If the manager is smart he would probably let you, if you're happy and want to come back he is doing a good job. :)

I have done it before when the bar did not have the type of mixer I wanted with my booze. The put it behind the bar for when I wanted a drink. No one complained.

Depends on the bar. Call or preferably visit the bar ahead of time.

No law against it, you may want to get the bartenders permission though.

No its like taking a tomato in to a cafe and buy a cheese sandwich to put it in.

No you are wrong

I don't think the bar would like it but I doubt there is a law against it.