A good effort, but there's way to much noise in the background and a wide halo around the stirrer. A bit of a visible tilt as well. I do like the colors and lighting here.
Back to comment: There are several cold drinks in this challenge and by adding a stir stick to yours you provided a strong focal point for the image. However, there is a lot of haloing around the top part of the stick from the post processing and there are weird reflections in the glass. The image also suffers from the lighting a bit but I have no suggestions for how to improve it. I would suggest you look at some of the images in the Recipe (Beverage) challenge and PM some of the higher scoring ones and ask how they set up their lights. I've done this a few times and almost everyone was more than happy to share their knowledge.