Sounds like you're coding up a "carousel" from scratch, which can be a fun exercise. However, if you want to just implement it and get on with your day, you might try a cycle plugin like jQuery Cycle. That link will take you to the page that shows cycling non-image content.
If you want to code it up yourself, you might write a function to do something like this:
// Do something with the "i"th item
You'll need to detect when you are at the beginning or end, and then fade the appropriate items. You can use a .delay() between fades, or use a JS timer, which is probably more robust.
Also, you can just use .fadeIn() and .fadeOut() to show and hide things respectively, instead of adding and removing classes. You would probably just make .drinks_content hidden from your CSS (display:none) at first, then fade it in.
Hope that points you in the right direction....