Why Dipping Cookies in Milk (As Well As Tea and Coffee) Is Scientifically Beneficial
When Greek NBA player Giannis Antetokounmpo first tried dipping his Oreos in milk a few months ago, he was understandably blown away. “From now on, this is my daily snack ,” he said during a press conference. ( Watch the clip below . It’s amazing.)
Dunking is such an important part of snacking that it has its own Wikipedia page . Ancient Romans dipped hard, unleavened wafers in wine, Proust famously wrote about dipping madeleines, and modern Australians engage in a snacking ritual called “Tim Tam Slam” or “tea sucking.” The British are obsessed with tea-soaked biscuits, and in the United States there is a chain of donut shops that have the word “Dunkin'” in their name. This practice is so ingrained in snacking culture that we don’t question it, but there are plenty of practical and scientific reasons for soaking.
First, it is mitigation. The aforementioned bland Roman wafers were quite tough on the teeth, and dipping them in wine made them easier to chew (and made them taste like wine, which I assume was an improvement). The dipping also softens Oreos and other British-style biscuits, allowing consumers to experience an alternate texture different from the one they experience when eating fresh from the package.
In terms of taste, dipping has two functions: smoothing out the flavor and enhancing the flavor. If you dip the cookies in milk, you will smooth out the harsher, sugarier qualities of the baked goods. In 2016, Matthew Hartings, professor of chemistry at American University, told Quartz that “part of this has to do with the chemical compounds interacting with our languages.” Milk contains a lot of emulsifiers, which prevent the separation of fat when stored in the refrigerator. These emulsifiers “help smooth out the chocolate as you eat it” while the moisture softens the cookies and helps your taste buds get the taste faster. The fat in milk also blunts any spicy or overly sweet flavors. (I’ve also noticed that it tones down some of the more synthetic flavors in mass-produced prepackaged cookies.)
Tea and coffee offer a different experience. We get the same emollient effect as milk, but without the dampening effect of fat, as well as a host of different flavor molecules, some of which can be found in both the drink and the biscuit. These chemical compounds interact with each other, coating our tongue and penetrating the nose, allowing us to experience both the snack and the drink in a new and interesting way. The toasty flavors in coffee and tea complement the toasty flavors in your baked goods, while the bitter, more astringent flavors in both soften the sweetness a bit and create contrast. It is really very beautiful.
Why doesn’t this work with water or juice? Simply put: molecules interact poorly with each other. Water doesn’t give cookies or cakes a lot of work—nothing to complement or contrast, no emulsifiers, and no fat. You get soaked cookies without any softening or contrasting properties of milk, tea or coffee. Juice contains many aromatic molecules, but often these are the wrong molecules, although there are exceptions. I’ve never dunked graham crackers in apple juice, but they’re nice enough when eaten side by side, and I’ve seen fruit-flavored cookies work with matching fruit juices. However, I would never recommend dipping cookies or any other baked goods in orange juice. Orange juice is very annoying.