Originally Posted by ChadChaney
Just because there is no visible signs of fermentation does not mean it is not happening! Use your hydrometer to check a sample real quick.
Wait until 72 hours then check the gravity! If you are using a bucket you may never see any activity. If you have even a small air leak you may not see any bubbling in the airlock. Krausen may rise and fall without seeing it happen. You may see some residue on the sides of the fermenter.