Does anyone know the effect of too much sugar in a yellow cake?  I was using a fluffy yellow cake recipe from Cook's Illustrated and forgot some of the sugar gets whipped into the egg whites.  I had doubled the recipe so I put an extra 1/2 sugar in the batter.  I ended up making another batch of the dry ingredients to be safe, but I saved the other mixture.  Any thoughts as to what the outcome might be in using too much sugar?

AI accidentally used twice the sugar called for in a chocolate cake recipe once. Boy was that a mess in the oven. It rose & rose & rose until it was running all over the oven. That might not answer your question, but it certainly taught me a lesson I won't soon forget. If you only used a little extra, your cake definitely will be sweeter. Your crumb can be effected because sugar is a tenderizer, and too much can weaken the structure of your cake. I would either scrap it or correct what you are working with. Also, if it is for a customer, I wouldn't sell a cake that isn't done right. I want consistency throughout all my products. One messed up cake may not seem like a huge deal, but if it goes wrong, you could lose a customer.

I appreciate your response, I totally agree and made another cake, but it was so frustrating!  The correct amount was three cups and I put in 1/2 cup too much, (the 1/2 cup was meant to whip with the egg whites).  I'm going to bake it, just for us, to see how it comes out, I hate to waste ingredients:-)

AOh, it drives me nuts to make a mistake that wastes a whole lot of ingredients. 1/2 cup extra sugar may not have effected the cake dramatically, but personally, I would have still baked a new one. Now your family gets to enjoy a cake too!