Why 1/2 tsp. of water needed in chocolate chip cookies?

Dear Cecil:

I would appreciate a scientific answer to this question if there is one. In making chocolate chip cookies, why is it important to add one-half teaspoon of water? Any real reason? For years the recipe on packages of Nestle's semi-sweet chocolate chip packages told you to do this, and the recipes on other brands still do.

Cecil replies:

There is only one way to obtain a “scientific answer,” and that is to conduct a scientific experiment. Which I did, under the controlled sterile conditions of my own humble kitchen. Following the Scientific Method, as laid out by countless generations of high-school chemistry teachers, I prepared two batches of the peerless cookie, one with the mysterious half teaspoon of water, and one without. End difference: zip. But the batch with the water seemed to make a less glutinous batter–it mixed better, came off the spoon with less resistance, and was, in general, noticeably more docile.

Send questions to Cecil via cecil@straightdope.com.

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