Terry, I certainly am not an expert. I do know the seed is not viable unless it is BROWN. Many seeds let go early and you get nothing.
I let nature do it's thing. I let the seeds fall where they may and leave them alone. That way I don't have to go through all the steps for stratification. It was my understanding if you go through the process, you had to soak in warm water for 24 hours. My thought was OK, use a small thermos. Then you were to keep in a damp mixture for a couple months or so and then in the fridge for another period of time.
Terry, I just don't have the time for all that so I chose the easy way. BUT I have more seeds germinate than I firmly believe any stratification could do. If you want to keep them separate, why not do a marked area or container for each and barely cover with a medium. I do not pot until they have 3 sets of leaves. Don't have a reason for that other than a better survival rate!
Sorry I'm not of any help or the expert you thought I was. :O(
Lynn

I am new to Japanese Maples. I have access to a full-grown ACER PALMATUM (green in spring red in the fall) that seeds every year. I decided to try to grow them by collecting the seeds. As an experiment I took seeds every month from Jun. until Oct. (Oct. being the month the seeds began to fall off). I found that the months of Aug. and Sept. germinated in the refrigerator by Feb. I planted these groups mid Mar. 2006 and they seem to be doing well in planting beds under plastic with shade. I am still waiting to see if the Oct. group will germinate by April.

Bill, thanks for the information.

Terry