I'm trying to make a beer in a glass in blender, and I am having an issue. I went to render it after I put the liquid in the glass to see how it looked, and the beer part (which is a separate object) is showing up in the bottom of the glass where it shouldn't. Can anyone help? By the way, I am very new to blender. If it helps, I was following the tutorial on blenderguru.com. http://www.blenderguru.com/tutorials/make-beer-blender/
In your file the liquid object and the glass object both have the same material. If you give the glass object a separate material without any absorption, it works as expected.
One of the way to do this is to make sure the liquid object is inside the glass object ever so slightly. Meaning the liquid object is a little larger than the internal surface of the glass object. So SCALE UP your liquid object by say "1.001" or "1.01"
This should be the result you get.
BLEND FILE EXAMINATION
Examined your blend file and found gaps between the glass and the liquid object. My suggestion is that you should apply the sub surf modifier on the glass and create the liquid beer object from the interior polygon surface of the glass object. Remember to flip your normals on the beer liquid object using CtrlN. Then scale it up so that you do not have 2 sub surf modifier on 2 separate mesh which you may have accidentally changed and mismatching their geometry.