Good question! ;) Might give it a try myself. Thanks.

You may have already seen this info site but thought I'd post it just in case. I interpret it to mean the variety of plum used can make a great deal of difference. And one other source I read said the sweetest prunes were left on the tree to dry because once picked they won't get any sweeter.

Dave

Here is a link that might be useful: How to turn plums into prunes

Well, you've got to have high sugar prune plums, which you do. Then they go into the dehydrator. That's the whole thing.

The commercial ones don't seem to be all the way dry. I'm not quite sure why they don't spoil. It makes me suspicious.

Home dried fruit is always going to be tougher and chewier than commercial dried fruit. We like it better. My son can't stand those gooey candy-like dried Turkish apricots. He says he wants the ones that darken and are a hard chew like leather.

If it helps you, I take my fruit out of the dehydrator when it is about 90-95% dry and let it finish drying just air dried. If the fruit is left in the dehydrator too long, it gets darkened like it is burnt.

I've got low humidity, so it is safe for me to do that. The dehydrators that you buy cook the fruit a little bit. I suspect that they keep the temperature above optimum to make sure they don't get sued for spoilage.

My son has promised to build me a solar dehydrator this winter, so I am hoping to get better dried fruit next year.

The commercial ones are sulfured, then dried. Often store dried fruits have also been put into a sugar solution.
They are not the same as home dried ones. You can buy sulfites and do them, but I have never tried it.

The commercial prunes are made with preservatives and then rehydrated. It's not really practical to expect to make those soft moist prunes at home.

You always used to have to soak prunes (and other dried fruit) before cooking. Goodness knows what they do to get the soft ready to eat ones that are on sale nowadays. I have an old French prune drying rack from the Agen region. It looks a bit like a snow shoe with wooden struts instead of webbing. It seems the fruit were just laid out on the racks and put first into the sun and then into a low oven. The link tells you more. There is no mention of any process other than drying ie no sulphur or sugar.

Here is a link that might be useful: Prunes d'Agen

I am using potassium sorbate as a preservative this year for the first time. It doesn't leave a taste, as sulfur does.