Chocolate genoise question

[oli]

I have a recipe for chocolate genoise and was wondering about a couple of things.
!. The recipe calls for a 9" pan. Can I use a 8" pan without having to worry about the cake coming out too tall, and that it ends up collapsing?

2. If I want to make it a chocolate genoise, do I half the flour recipe and add cocoa powder so I still end up with 1 1/3 cups of combined flour and cocoa?

Or do I just add a certain amount of cocoa to the 1 1/3 C flour?

2 ounces unsalted butter
1 1/3 cups all-purpose flour, sifted,plus more for pan
6 large eggs
1 cup sugar

[Jock]

If you are talking about a round cake pan, an 8" pan is about 0.8 times the size of a 9" pan. So, if you multiply your ingredients by 0.8 you can keep the same proportions in the smaller pan.

I'm not a baker but I think you would need to keep the same volume of flour because that is what gives the cake its structure. With such small proportions I don't think you would need much cocoa - maybe a tablespoon or two. You would also need to increase the sugar as well to compensate. When the sugar disolves in the egg, it acts like a liquid and should be enough to account for the little bit of extra dry ingredient.

Jock

[oli]

So If I am reading you correctly, all your saying is add a little cocoa to this recipe and some more sugar and I should be okay in the 8" pan. My own recipe,not the one posted, went into a 8" pan but was only 2 3/4" tall and I wanted a recipe that would give me a little more height, perhaps 3" tall, so that, when I slice through to get my three layers, they would be a little bit thicker a piece of cardboard

[Jock]

OK, same disclaimer as before - I am not a baker and these are just my opinions, but.....

Yes, I'm saying just add a bit more sugar to sweeten the little bit of cocoa and you should be good to go.

As to the 3" high cake, that's a bit trickier. There is no mechanical levener in your recipe (baking powder for example) and the lift is presumably from the airation of the eggs when you beat them. It's also what gives the cake its wonderfull light texture. That being so, there might not be enough structure to hold up a higher cake without it collapsing. I will defer to the experts on this one.

Jock

[panini]

Late into this post as usual. We cut the amount of flour and make the difference up with cocoa. 8,9.10" doesn't matter. You will just neeed to scale back the amount.
I can't remember the percentages right off. I'm thinking we use 3Lbs 4oz sifted flour for a twenty quart. and we use 3 flour and 4oz cocoa
hth