Charles
My first attempt at making onion seeds appears to be a success, given that I appear to have upwards of 1000 black gems in a tureen now totally dry.
Either due to poor planning, incompetence or what have you, there are also dried seed husks and seedhead stalks in there too.
I have managed to separate around 200 seeds so far using a teaspoon, but it is really time consuming and about as interesting as watching paint dry.
Have you ever had this issue and if so, did you find a sieve of the right pore size to effect separation (I tried the fine soil sieve and everything went through it!)? Or another efficient trick??