Last fall, I was making cookies for a visiting diabetic family member and decided to try substituting Splenda® (sucralose) in place of sugar in the recipe. Now, I’ll admit right here, I did not use SPLENDA® Sugar Blend for Baking, which contains real sugar. I used 100% sucralose and the results were so bad that I can see why baking Splenda® was invented.
My initial concern was that the resulting dough would be too moist, since I knew that a smaller volume of sucralose would be required to replace the sugar. However, I soon realized that I had the opposite problem. These were some of the driest cookies that I had ever baked. What went wrong?
When you think about it, cooking is just one big chemistry experiment. And since sucralose has a different molecular structure than sugar, it makes sense that it would react differently than sugar. My first working theory was that, in this recipe, water must be liberated from the sugar during the baking of the cookies. What else could explain the extreme loss of moisture?
Thanks to The Culture of Chemistry, I learned that “sucralose [Splenda] is made by chlorinating sugar, that is replacing 3 of the 8 hydroxyl (OH) groups with chlorine atoms.” Aha! Remember that the molecular structure of water is H2O? You can also think of water as a bunch of H+ ions bonded to OH- ions. Or, to put it another way, based upon molecular structure alone, sucralose should be 3/8 less likely than sugar to contribute to the formation of water (or moisture) in my cookie dough.
But does the chemistry really work out that way? I’m not sure. How much does baking really alter the composition of sugar? And my problems seemed to begin prior to baking.
So maybe there’s a simpler explanation. I found several online cooking forums that discussed the importance of sugar for moisture retention in baking. This led me to my second working theory: maybe sucralose does a poorer job of holding onto the moisture from the eggs and shortening.
In the article "C" is for Cookie, Brian Strouts, head of experimental baking at the American Institute of Baking in Manhattan, KS, is quoted as saying, "During the initial creaming mixing stage, sucrose [sugar] particles are coated with a layer of fat … When the cookie dough piece warms in the oven, the fat layer melts away allowing the water to migrate to the sugar and go into solution. As the sugar changes from solid to liquid, it causes the cookie to flow or spread."
Aha! So maybe that was my problem. Since the sucralose and shortening didn’t blend well to begin with, this process was altered. The sucralose didn’t go into solution with the water when the cookies were baking so the moisture was lost.
But are either of my two theories right? It's been six months now and I still don’t know.
And that’s what is nice about science. You can always develop a working theory (or two) and replace it with a better theory when you learn more or obtain new information. So, if you know what happened to my cookies, drop me a line and let me know!
Whatever the reason, I’m certain the chemistry of Splenda® is to blame. It couldn’t possibly be my baking, now could it?