The Krausen is 2 to 3 inches thick and very active, the airlock is also very active. Upon thinking about it the temp is set to 11.6 degrees C, given that fermentation is exothermic (I hope I spelled that right) the temp of the beer should be closer to 58. I tried strapping the sensor (Ebay Aquarium) to the outside of a glass of water before brewing and had wild temp swings. Now the sensor is wrapped inside of a balloon submersed in the glass of water-not measuring the temp of beer but holding very steady.