They're mechanically pitted using an industrial cherry pitter (a small operation may use something like this; the larger ones are huge) and then dried in an dehydrator (a small scale operation may use a tray dryer like {{gwi:95743}}; a large operation will generally use a belt dryer like {{gwi:95744}}.). Some operations also do freeze dehydration (depends on whether you want the fruit leathery or not). Sugar is optional, and depends on the flavor you want in the dried cherries. Check your package to see if they use it.

At home, you can pit them yourself and then use a normal kitchen dehydrator. If you do want to add sugar, I'm not sure how the sugar is added, because I never sweeten anything I dehydrate. I'd probably try quickly dipping them in a strong, hot sugar syrup before dehydration.

This is a perfect question for the Harvest Forum.

Carla in Sac

Here is a link that might be useful: Harvest Forum Garden Web

Thanks, everybody, for your advice. I think I'll try the syrup idea, as I suspect that sour cherries aren't going to be very sweet even when dried. Though perhaps I should sample a few first to see. I actually like fruit that is somewhat on the tart side--as my favorite apples are Granny Smith. So perhaps I could develop a tase for unsweetened cherries as well!

Just a warning -- attempting to dehydrate cherries in a home dehydrator is an exercise in patience and electricity consumption.

Another family member was successful at drying apples in our gas oven last year, using just the pilot light. So I thought I might give that a try with the cherries too, as it won't cost anything. Of course, if somebody forgets they are there and turns on the oven, I could end up with roasted cherries instead of dried ones!

Mom used to dehydrate stuff in the attic in the summer. Worked like a charm.

There are some safety aspects to fruit dehydration. There's a great summary here:
http://www.ext.vt.edu/pubs/foods/348-597/348-597.html