Some thoughts for you out of left field here:
Am wondering if you might be able to achieve the goal you want more easily and cheaply through trademark than through patent protection.
If your container construction works somehow with the drink to create a novel and useful combination, then as the patent people have pointed out you may be able to get patent protection for that combination, but it could also be difficult and expensive to succeed with that.
On the other hand, if your primary concern is just to make sure no one else imitates your idea in trying to sell this drink in this kind of container, you might want to explore whether trademark law would get you where you want to go. Packaging or containers can count as trademarks if they are functioning as trademarks -- like the unique shape of the old coca cola bottle. (When packaging serves as a trademark, it is known as "trade dress".)
Patents last 20 years from when you apply for the patent and preclude anyone else from making, using, or selling your invention without your permission. A trademark, if properly used and protected, can last forever; its focus however is not on the USE of your technology, but rather on the SELLING of your goods. A trademark is a name or symbol (or package design) which the public recognizes as an indicator that all goods with that name or symbol (or package design) come from one source. Trademark infringement occurs when a competitor uses a similar mark which creates a likelihood of confusion in the minds customers as to the source of the goods.
Patent law will protect your idea if it's novel, useful, and non-obvious; trademark law is more concerned with marketing (and helping consumers): it protects the symbol you've chosen to set your goods apart from other similar goods in the market place.
So while trademark protection would not keep other people from making or using of their own combination of the container with the drink in their own homes as a patent would (at least theoretically), trademark law might be able to keep others from selling the drink in any similar looking container.
If you think this approach might suit your needs, talk with an IP attorney who understands both patent and trademark to see which area of law is better suited to your goals in light of the practicalities of the full facts (which you are wise not to spell out here) and your budget.