I hope to make all my blog posts unique and interesting in their own ways, this Culinary Chemistry is particularly special. This post features a highly anticipated guest star: Mama Renée herself! Without her help in this endeavor, the following would have most likely been horribly botched if not completely impossible.
I solicited my mother’s help for this project because, despite my extensive chemical knowledge – or so I like to say -, making toffee and caramel is her domain of expertise. I also needed her input because the following recipe is a family tradition which was passed on from her grandmother to her and henceforth to myself. (see picture to the left for two-thirds of the Renée clan)
Additionally, the process of caramelization is a chemically interesting mechanism to examine. To begin the process of caramelization first one must obtain a carbohydrate of some kind. This should not be terribly difficult seeing as this is basis of most foods such as a sugar found in fruits and vegetables. Naturally, I used cane sugar because this is the most readily available kind of sugar. Over light heat, the carbohydrate breaks down first by letting go of the “hydrate” in the form of steam. Now, as the product is continually heated it will let go more and more of the water and reduce to simply carbon. This would not be a terribly edible snack so it is best to not let it progress to that extent.
As the sugar continues cooking and letting off steam it should begin to change color. Note that color change is an extremely important evidence of reaction and generally indicates chemical change is occurring.
The following steps occur fairly rapidly and in ways that are not easily comprehensible to anyone who has not been through the emotional turmoil that is an organic chemistry unit. First, the compound sucrose, a disaccharide, breaks down into glucose and fructose, two monosaccharides. Next, the two compounds react to dehydrate and form polymers. This water is lost as steam, as mentioned above. The word polymer simply refers to a repeating chain of repeating units bonded together to form one giant structure. Giant, that is, on a microscale. From here several different compounds are formed:
Furans, which have a nutty taste and aroma. Diacetyl, which smells buttery. Maltol, which can only be described as tasting warm and cozy. Finally, ethyl acetate which is a common organic compound associated with fruitiness. The ensemble of these taste creates the final product: caramel or, in this case, toffee.
While I find the chemistry aspect of this experiment to be lovely and endlessly interesting, I realize that actually eating the toffee may be much more appealing for those not thrilled with the mechanisms of polymerization and oxidation. See recipe below for instructions on how to make your own.