If you get a 12 pack of beer cans and a twelve pack of soda, they weight the same. A six pack of soda bottles and a sixer of malt liquor weigh the same.

Go to a self checkout with a basket or something, and make sure no checker that cares is paying attention. Ring the soda, and put beer in the bag. use a paper bag, because they can see thru the plastic ones. Don't put the soda in the bag or it'll mess up the weight. Pay, and leave. quickly.

I don't believe you get carded for ringing up soda.

I can't even count the ways that will most likely get you all kinds of busted.