Expert: Robert Connolly - 4/9/2007

Question
I am helping my 12 y.o. neice with her school science project.  Our
experiment will be altering the ingredients in Nestle toll house chocolate chip
cookies and observing the results.  One batch will be the standard recipe
(control).  The other three will be a) lacking butter, b) lacking eggs c) lacking
baking soda.  I believe I can predict a) will be crumbly, b) tough c) flat.

In any event we will do the experiment in the coming days to see the actual
result.

My question relates to the theory of each ingredient.  I know oil and water do
not mix, eggs serve to emulsify, baking soda will provide the small gas
bubbles to help the dough rise...  Can you help us in regard to providing the
scientific theory which might be presentable to 5th and 6th graders?

I have a PhD in Molecular Biology, B.S. in Biochemistry.  I'm sure your
explanations will be easier to understand than those I might try.  

I do enjoy all forms of cooking but am self taught.  Perhaps a professional
baker or chef will arise from this group of cookie eaters.  Please help.

Thank you.

Her project is due 4/18/07.  As her Uncle I intend to do a trial run tonight    
4/8/07.  Then we shall devour the evidence.  (or throw it out).

Richard D. Rasmussen
Grants Pass Oregon

Answer
rich, i have spent the last 30 years in a commercial baking enviornment making all sorts of things requiring a multitude of components, the properties which each ingredient lends to a recepie is not my area of expertice,sometimes we just have to trust our instincts when we approach a new concoction and usually we get a good result so i can't be of much help here,just write down your observations as honestly as possible and throw the chemistry out the window for now,some of the things that happen in a baking enviornment we just cant explain! good luck! bob connolly,www.millsbakery.com