Having problems dehydrating apples

I have my own orchard and have started making fruit leathers. I've found the best way is to chop and cook the apples until soft, blend in a food processor with some lemon juice and cinammon. Nothing else. Then spread on a silicone sheet 0.3in deep. They go in my Excalibur 9 tray dehydrator. I usually run it at 135F (57C) for 10hours as recommended but I find 99% of the time the leather is simply too tough and thin. For some bizarre reason, I did one variety once (i forget…

Having problems dehydrating apples