This is occuring simply because of the three layers (on each side) in the glass object. What you're experiencing was commonly known as "The Dreaded Blue Gunk" back in versions 2 and 3. Mostly fixed for version 4, but there are still occasions when it shows up, like this one. Cure: open the material editor for your glass and liquid materials. Set the fade-out colors to white (for the light one) and to black (for the dark one). You'll notice an immediate improvement in the render appearance of all glass objects, and it will erase the blues from this one. :)