Best time to cut Hydrangea blooms for drying
 

I've managed to get my indoor hydrangea to bloom outside in a pot. It's
beautiful and blue without the help of aluminum sulfide. Of course I want to
keep the blooms and dry them. When should I cut them off the stem? They're
in full bloom now and have been for about 2 weeks. When it comes to the
drying part, what is the best procedure? Ugh, thanks for your advice.