Adding salt to ice will make the ice colder.

Most cooks know that a splash of lemon juice keeps freshly peeled and quartered apples from turning brown. But chances are they rarely equate this preservation method with putting a coat of primer on a car.

In principle, it’s the same thing. Just as the paint prevents the oxygen in the air from mixing with the iron in the car and rusting, the acid in the lemon juice keeps oxidation at bay and the apples from turning brown.

You can chalk up that lesson up to chemistry.

While the warmth and comfort of a kitchen might seem far removed from the sterile and exactness of a laboratory, in fact, the two share many properties. Knowing a thing or two about chemistry can help cooks from making the novice mistake of substituting baking soda for baking powder or adding that extra cup of sugar to turn cake batter into pudding fodder.

Chef superstars — such as Alton Brown of “Good Eats” and Ted Allen of “Food Detectives” — have brought the chemistry of cooking into the mainstream.

Larry Fullerton, who once taught a very popular food chemistry class at Perry-Lecompton High School, says understanding the chemical reactions in food will help when you want to experiment in the kitchen.

“We try to show you what is happening isn’t magic,” says Fullerton, who now teachers chemistry and physics at Free State High School.

His hands-on and sometimes edible experiments include the egg, whose proteins, when heated, allow cake batters to crown. And they help bind ingredients together.

Another lab shows how putting salt on ice makes it colder. Luckily for his students, that lesson came with hand-cranked, homemade ice cream.

For cooks who follow recipes to the one-eighth of the teaspoon, understanding chemistry might not be all that important, says Coleen Creed, a family and consumer science teacher at South Junior High School.

“But when you want to develop your own recipe or adapt one, you really need to understand the whys,” she says.

In one of Creed’s food courses she breaks the class into groups and gives each one recipes that only vary by an ingredient or two.

With flour, salt and water, one group makes hardtack. By adding shortening to the mix, another group bakes a pie crust. Then the addition of baking powder to those ingredients results in biscuits. And the final two variables eggs and sugar produce cookies or cake depending on the amount of the ratio.

If it sounds an awful lot like a controlled science experiment, that’s because in essence it is.

“Basically that is what cooking is: It’s a chemical reaction where combining different elements and effecting it by heat and by the cold and the ingredients determine the end product,” Creed says.

So how do chemists do in the kitchen?

While not a scientific study, a chili cook off at one high school where Fullerton taught had three faculty members all with chemistry background taking top honors.

“We swept it,” he says.