The January post is on the chemistry of caramels. It can be found here, in The Boston Globe Magazine, and a version is reprinted below.
My 14-year-old son Ben loves to cook. He enjoys grilling, creating his own spices, baking cookies for his class, and preparing meals when we have friends and family over for dinner.
Making caramels is one of his favorites – fleur de sel caramels – from Ina Garten’s cookbook How Easy Is That? As Ina puts it, caramels are “a perfect candy happy ending” to a delicious meal.
Because of the high heat involved, I used to help Ben, acting as his sous-chef. After watching the sugar transform to golden brown and the final mixture gradually thicken, I began to wonder what’s actually going on. So I did some reading and learned that caramels provide all kinds of lessons about cooking, chemistry, and raising children.
The first step in making caramels is caramelization, the process of heating sugar until it turns into a golden brown, aromatic liquid. This is truly a remarkable transformation. The sugar goes from solid to liquid. The color changes from white to pale amber to golden brown. Crystal sugar has no smell at all, but liquid sugar has a complex bouquet of aromas. And the flavor changes from simple and sweet to richly complex and nutty.
It’s hard to see the changes moment to moment – it’s so gradual. Yet what we end up with is so different from what we started with. I can’t help but think that the same is true of children.
What happened? As sugar is heated up, hundreds of new chemicals are produced. Some are volatile – they vaporize – so we can smell them. Some are responsible for the flavors we associate with caramels – nutty, buttery, toasty, even fruity. And some make new connections with each other, forming molecules with names like caramelans, caramelens, and caramelins (I’m not making this up).
While Ben and I caramelize the sugar, we also heat milk, butter, and salt in a separate pot. Then the two mixtures are combined. We have to go slowly or it will bubble over. We continue to heat it until it reaches a key temperature – 248 °F – on our candy thermometer.
I have to be careful so that nothing (and no one) gets burned. I used to do this step for Ben. Later, I hovered nervously as he poured the hot liquid himself, his sleeve sweeping precariously over the flame. Now he tells me he knows what he’s doing.
This is a second seemingly magical transformation.
The molecules in the sugar mixture combine with proteins in the milk and butter. Like in the process of caramelization, hundreds of new chemicals are produced. This reaction goes by a name – the Maillard reaction – which is not one chemical reaction, but many.
If we stop the process too early, the consistency isn’t right. If we let it go too long, it burns. That’s why 248 °F is so important. We can’t see the molecules doing their thing – the thermometer gives us a window on the chemical process happening right under our noses.
Cooking caramels with Ben – or cooking anything for that matter – is all about chemistry.
Surprisingly, chemists do not fully understand all of the chemical reactions that take place during caramelization or the Maillard reaction. But, as with any chemical reaction, atoms are not changed, but atoms that make up molecules change partners. This is the essence of chemical reactions and cooking – old bonds are broken and new ones are formed.
Ben now makes caramels by himself. He no longer needs my help. In many ways, he has been transformed through cooking – from a young child needing help and guidance to an independent young man who can navigate his own way through a recipe and the kitchen (and elsewhere).
And I have changed too, not just recognizing the close connection between cooking and chemistry, but also willing and ready (almost) to let Ben learn and explore on his own – which feels, to me, both sweet and salty.