I can't imagine that the introduction of fluid would degrade the protein component of the powder, but I'm no expert. If it were a major concern I suppose one could bring the fluid in a container and wait to mix the shake (though I know using a blender works so well!). Personally, on the odd day I do a protein shake for lunch I blend it up in the morning and don't worry about it.
47 M 5'8"
May 4, 2010...... 440? lbs. (Start FitDay Size 60 Jeans)
June 19, 2010.... 393 lbs. (First Weigh-in)
June 19, 2011.... 229 lbs. (164 lbs. gone in one year :-)
Current Weight... 185 lbs. (Size 36 Jeans)
Next Goal 169 lbs. (07/04/12)
Ultimate Goal 165 lbs. (12/31/12)
The best exercises for weight loss are Fork Putdowns and Table Pushaways.