You're right - I didn't have any problem mushrooming - I filled each mold w/ 70g batter, and they rose just up to the top, with the center bulging slightly upwards, but the edges not going past the mold, so that's not the problem.
I had assumed I had too much lubrication, hadn't considered that I might have too little. They did just slip right out of the molds when I flipped them upside down (didn't even really have to tap them), which I would think wouldn't be the case if I didn't have enough coating.
This is interesting, and the first explanation I've been able to find. Thanks! I might experiment with it at some point in the future, but for now I'm not going to add that variable into my experiments since the height of mine seems fine, and I'm not having mushrooming problems. Maybe that's also less necessary since I'm preheating my baking stone to 500 about an hour before baking, so that provides enough shock without the added chilling?
OK, this is good to know, too. Maybe I'll drop the temp a minute or so earlier. I'm only doing 10 min at 500, rotating after 5, before dropping the temp. Actual temp will drop more slowly since I'm using a stone, though.
Thanks! Yes, we had no problem eating the second batch, either :-)
I've got enough batter for 12 ready to bake today. If anything, the wax-butter coating should be a little thinner than last time since I tried to apply it hotter and didn't let it dwell at all in the mold -- filled to the rim and them dumped it out immediately. Here's a pic of the coated mold in case you can see anything from a picture... I'm going to bake 4 this afternoon to see how they turn out. If they still have white tops, I'll probably re-coat the next 4 and try to get the coating to be a little thicker.
Thanks,
Mike