The physics of oreo cookies

Last edited Sun May 8, 2022, 01:07 PM - Edit history (1)

WEEKEND READS: WHAT A TWIST!
MAY 7, 2022 EDITOR
by Kevin Schofield

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For while it is indeed a paper on fluid mechanics with the required complicated mathematical formulas and squiggly-line Greek letters, it probes one of the deepest, darkest problems of the universe: predicting what happens to the creme filling when you twist apart an Oreo.

In fact, the authors, two MIT researchers, coined a new term for the study of this phenomenon: “Oreology.” This is a clever twist (no pun intended) on “rheology,” the official term for the study of the flow of materials with complex viscosity, such as Oreo creme. This isn’t the first time rheologists have applied their craft to food; for many decades, food scientists have studied how to thicken sauces, sweeten chocolate, tune the flow of fondue, and give ketchup and mayonnaise just the right texture. But twisting apart an Oreo goes one step further, into “parallel plate rheology,” or what happens when a thickened fluid is sandwiched between two moving parallel plates (e.g., chocolate wafers).

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These outcomes didn’t vary by the flavor of the creme, the rotation rate, or by the amount of “stuf” in the creme layer. What did seem to matter, though, was the age of the Oreos and how they had been treated over the course of their short-but-oh-so-tasty lives. The researchers noticed that in some Oreos, the creme had creeped out to the edges of the cookie, as one might expect over time or if the package was stored in a hot room: The creme is still a liquid, albeit a very thick one, and will still spread under the right conditions. Those cookies that showed signs of the creme spreading out were more likely to split the creme between the two wafers.

The researchers then proceeded to the next critically important topic: what happens when an Oreo is dunked in milk…
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https://southseattleemerald.com/2022/05/07/weekend-reads-what-a-twist/