Changed baking stones, now having a crust issue! Help!
Hi! I've been bit by the baking bug. Specifically baking artisan bread using the no-knead method. I've had great results with a simple baking stone from Pampered Chef, but recently I thought I'd treat myself and upgrade to a more expensive, larger, thicker stone. This  one to be exact. I've used it twice now and my bread has come out of the oven with a nice crust on top, but the bottom was mushy and underdone. The first time, I had preheated the stone in the oven at 450 for 20 minutes, which had been working with my Pampered Chef stone. The second time, I gave it a 40 minute preheat and it made no difference. I'm bummed because the stone was $50 and the store won't take back used items. The reviews on the website say it makes great bread, so I'm hoping there is some tweak that I'm not aware of that will help me love my new stone! Any advice would be appreciated.