Issue with Volume Absorption inside Glass first time posting here and very new to blender, Im following BlenderGuru's latest tutorial and I'm having some issues with volume absorption, this is of course not a job, I don't have a deadline, so I wanna know what is wrong with it and how to fix it not just do it in a different way. 

I rendered each picture at 128 samples using denoiser with cycles in blender 2.80, I'm not sure the exact value I applied to the volume as I changed it a lot to check different results and they were all basically the same, with that foggy look, however it should be at around 700 for this one.

One thing I noticed is that the material looks a bit different in the material preview than in the last picture here where it looks opaque on the sides while in the preview it looked glossy

In the first one the water is the same material as the cup, so you see there shouldn't be an issue with the geometry

Edit: Just found a way to add the blend file so is easier for you to check http://pasteall.org/blend/index.php?id=52500
I was facing the same issue when doing the Blender guru tutorial. I tried searching in a lot of threads for multiple hours but did not find a solution that worked. Then, I found an alternative method from a blender StackExchange thread that worked quite well for me. It talks about tweaking the IOR values of the faces of the coffee which face the glass.  The link for the thread is given below -
Liquid IOR
Image before tweaking the IOR value-

After tweaking the IOR value of the coffee faces by following the solution in the link and setting it to 0.8-

IOR set to 0.91 based on the formulae used in the link-

You can play around with values further to get the desired look.