Milk and cookies go together like peanut butter and jelly, salt and pepper, Jay-Z and Beyoncé. However, there is a right way and wrong way to dunk a cookie in milk, according to scientists. In 1998, a professor at the University of Bristol in the U.K. looked into the ideal method for dunking a British biscuit (aka a cookie) into a drink, using the concept of capillary action — the way fluids move spontaneously through small tubes in porous materials — and Washburn’s Equation, which describes their journey. Eventually, he determined that the typical British biscuit is best dunked for 3.5 to 5 seconds. Using this same technique in 2016, scientists at the University of Utah’s Splash Lab determined the perfect dunk time for the much-beloved Oreo. Although the amount of time to get to “perfect” depends on preferred sogginess levels and milk fat content, the Utah researchers determined that three seconds was enough to thoroughly saturate the Oreo without losing structural integrity.
Here’s the journey in slow motion. Cookies are porous, and milk travels through the small holes inside them the same way ink does through blotting paper, or a spill through a paper towel. During tests, the Oreo soaked up 50% of its potential liquid weight in one second. That number shot up to 80% at two seconds, flatlined at three seconds, and maxed out at four seconds — meaning the cookie could absorb no more milk. So if the goal was to saturate the cookie but not lose structural cohesion, three seconds was the perfect number. While this test used 2% milk as its dunking medium, the optimal dunking time will vary slightly when using other milk: The higher the milk fat (like whole milk or cream), the longer a cookie can be dunked, but only by mere fractions of a second. Mmmmm, we just made ourselves hungry.
Media Release/InterestingFacts.com
