What is the ideal consistency for a sponge cake?

[shovetheholly]

I've got a Kenwood chef and I'm experimenting with different ways of making a classic sponge.

I've found the K-beater (in both rubber and non-rubber guises) useless. I can't seem to get enough air into the cake with it to allow it to rise.

So I'm using the big whisk. It's producing a much better rise, but the texture is really, really soft. Almost like a madeira cake. It's very pleasant, but I'm not sure it's 'right'? Advice??

Personally I use the same tool as you and get similar results. I've always been under the impression that a sponge should be pretty much what it says on the tin and have a slight spring to it. So long as it's not crumbly I think you're fine

I never know how much to beat it! How do you know when it's 'done'? Can you overbeat it?