We are a forum for making wine, not for drying fruit and flowers. That said, we all freeze our fruits and flowers before making wine out of them, it breaks down the cell walls and makes juice extraction easier.
Elderberries and elderflowers are very easily frozen for future usage.
There are many websites online for dehydrating fruits, flowers and herbs.
GUAPO, stand by and wait for a response from LUC, he seems to speak this elderberry thing better than most, but he is in Europe so the time thing is different. And having said that,...welcome to our group/