Beer bottle

Hey guys i really want to lear about product design in 3d, i work with a lot of beers (i`m graphic designer) and i really want to make beer bottles and stuff, i really want to learn how to make the liquid inside, the water condenseation etc… i know how to make the bottle, recently i learn how to use volume absorption to make the color but i dont know how to make the liquid inside, and when i try to make de water condensation (drops) always have problems because the drops remain inside the bottle and not outside (i use solidify in the bottle) if u have a tutorial or something that i can learn I’d be really grateful.