In general, no. All stone is porous to some extent, however granite has very little porosity relative to other stones. Most granite colors will never show moisture but some colors will show a dark spot if a puddle of liquid is left on the counter for a period of 30 minutes of more. The spot will eventually dry up and evidence will show. To be safe, be sure that your granite is sealed properly – either by the fabricator, or after the granite is installed.