Is it safe to make cherry syrup using cherries that still have the pits?
I just made a quart of cherry syrup and didn't bother to remove the pits, since I would be straining off the liquid. Then I read that cherry pits are poisonous. I strained the syrup well, with no pieces of pits, but I did press down on the cherries as I was cooking them, to make certain I was getting all the flavor from them.
Would the cyanide level be dangerous the way I made the syrup?
The procedure you used is the one recommended by USDA for getting juice from cherries to make jelly (see http://nchfp.uga.edu/how/can_07/cherry_jelly_liquid.html ) so it is an approved process. It is a larger concern if you crack the pits open, or eat the pits in large amounts.