Baking in a convection oven

[lentil]

Can someone please tell me where I went wrong?

I was having a big baking day at work on Friday; I had bread and rolls in the gas ovens so I put biscotti and fudge brownies in the convection oven set at the recommended temp in the recipe. The brownies came out more rubber-like than fudgey and had raised itself off the bottom of the pan so they looked to be about 4 inches thick. When cut, the bottoms were completely uneven. They cooked through and tasted fine, but looked very strange.

And the biscotti, although it was nicely browned and seemingly firm, was completly uncooked in the middle. I sliced it anyway and placed the biscotti back in the oven as required. I called them "Barely Botched Pumpkin Cranberry Biscotti" and sold every one by the end of the day, but would prefer they looked a lot better...

Short of using the conventional gas ovens all the time, what techniques can you share for baking in the convection oven? Do I lower the temp 50 degrees as the Prof Chef recommends? Do I reduce baking time too? I think I understand why the biscotti weren't cooked in the center, but what the heck happened with the brownies?

Even though I sold out of the baked goods, I don't want to be known by my botched baking.

My convection oven no longer has the option of shutting the fan off. Don't ask...

[momoreg]

I had an oven like that once, with a constant fan. Such a pain.

The convection can have a bad effect on sheetpan-thick items like brownies and lemon bars. Lowering the temp. may at least make the bubbling underneath less drastic.

The biscotti not being done in the center is more of a temperature issue than a convection one. I haven't had probs with biscotti in a convection.

[waltersg69]

The fan has everything to do with it. You do have to reduce the temperature by 50 degrees (sometimes more) and probably increase cooking times. You also have to consider the load of the oven. That is, do you have 8 sheet pans in there or one? The brownie results sound like another factor is involved, like overmixing or one of 1000 other possibilities.

[lentil]

Walters, Thanks for your reply re the convection. The fan is permanently on due to an oven mishap prior to my employment. It cost $1100 to fix the last problem and the tech put a piece of electrical tape over the fan switch with note that said "DO NOT TOUCH!!" If I value my employment, I will NOT touch the fan switch.. I can only imagine how much the bill would have been had the fan been taken care of. Maybe it's a battle to be fought when business picks up again.

I had baking orders for Thanksgiving , but basically chickened out and used the conventional gas ovens. I'll do the same for the Christmas orders. The convection is in limited use; cookies, fish... I've actually come to appreciate the conventional ovens again.

I didn't load the convection. We're a pretty small kitchen, although I would have around the holidays had it worked better. C'est la vie

I'll watch for the over mixing. Since I'm alone except for a couple of part time kids until spring, I tend to do too many things at once. Thanks again.