Wondering if anyone has any suggestions. Trying a Hefeweizen. I boiled 3.4 kilograms of wheat LME in 5L water. Adding hops at 60 min, and 15 min. Cooled to 20deg C in ice bath, made up to 21L in fermenter and added dry hops. Rehydrated safbrew yeast at 40C and pitched yeast into wort which was at 20 degrees C a bit of action in the first 12 hours, but not enough to get the airlock bubbling. Thought rehydration killed yeast so pitched another sachet dry the next day. Still no action. Don't know what went wrong. Any ideas? Fermenter is in a stable 19 degrees fridge. Thanks.