Apparently the perfect dunk lasts between 3 and 4 seconds but again that depends on how you like your cookie. Do you like it crisp with a bit of milk, or do you like it mushy?
Apparently, a professor of physics ran some experiments back in the 1990's at the University of Bristol. He created a controversy when he stated that he could use the mathematical formula for capillary action to determine the answer to the question of dunking Oreos in milk. In case you are a bit rusty, water molecules have the ability to stick to solid surfaces. When water enters small tubes, it can seem to crawl up the tube as seen in straws or in paint brushes.
In other words, its the capillary action which helps milk spread through the small holes in cookies. As a matter of fact, an American scientist created the formula for this as applied to milk. Basically, it states that the distance the milk must travel is equal to the surface tension of milk times the average diameter all divided by four times the viscosity of milk.
Originally, the scientist applied the formula to ink and how fast it spread in ink blots but it was the British gentleman who applied the same formula to baked goods. After he determined which numbers were best for the variables, he rewrote the equation to solve for time since the question referred to the time you dunked a cookie. He actually used a standard British cookie and discovered the time ran between 3.5 and 5 seconds but he didn't use Oreos at all.
In 2016, another group decided to test Oreos using the formula along with Chips Ahoy, Nutter Butters, and Graham Crackers. They collected data by dunking each brand halfway into 2 percent milk for times ranging from half a second to seven seconds. They discovered that Oreos absorbed 50 percent of their potential liquid weight in one second, 80 percent in two seconds and by the fourth second, it reached it maximum and could not absorb any more. They concluded that after 5 seconds, the cookies were unable to absorb any more milk.
Then this same lab dunked each brand of cookie into water for six seconds and then hung them up to see how long it was before they collapsed. Graham Crackers only lasted eight seconds while Oreos lasted a full five minutes. Their final conclusion on the Oreos was that the optimum dunking time is at three seconds for maximum saturation and if you dunk more than four seconds, there is no additional benefit.
However, there is one more factor in this scenario. If you change the amount of fat in the milk, it could change the conclusion because the fat in the milk can slow down the absorption of milk. Furthermore, the sugar in the milk can also effect the absorption rate so be aware of that. So there you are, the mathematics behind the conclusion of why the ideal dunking time is between three to four seconds. Let me know what you think, I'd love to hear. Have a great day.
