How long and at what temperature should I dry out the porcinis to make them brittle?

I did buy dried porcinis but the recipe says if they are still pliable to dry them in the oven. Is the answer still the same, dry at 150 ( I'm guessing not for 2 hours).

This recipe calls for already dried porcinis -- an ingredient you can readily buy at supermarkets -- but if you'd like to dry them yourself, slice them on a mandoline, and dry them in a 150 degree oven (200 degrees with the door cracked if your oven doesn't go that low) for a couple of hours, turning once halfway through.