Why Do Oreos Never Come Apart Evenly?: MIT Researchers Build an “Oreometer” to Find the Answer

Despite hav­ing been around for well over a cen­tu­ry, the Oreo cook­ie has man­aged to retain cer­tain mys­ter­ies. Why, for exam­ple, does it nev­er come apart even­ly? Though dif­fer­ent Oreo-eaters pre­fer dif­fer­ent meth­ods of Oreo-eat­ing, an espe­cial­ly pop­u­lar approach to the world’s most pop­u­lar cook­ie involves twist­ing it open before con­sump­tion. That action pro­duces two sep­a­rate choco­late wafers, but as even kinder­garten­ers know from long and frus­trat­ing expe­ri­ence, the crème fill­ing sticks only to one side. It seems that no man­u­al tech­nique, no mat­ter how advanced, can split the con­tents of an Oreo close to even­ly, and only recent­ly have a team of researchers at the Mass­a­chu­setts Insti­tute of Tech­nol­o­gy sought an expla­na­tion.

This endeav­or neces­si­tat­ed an inves­ti­ga­tion of the Ore­o’s rhe­ol­o­gy — the study of the flow of mat­ter, espe­cial­ly liq­uids but also “soft solids” like crème fill­ing. Like all sci­en­tif­ic research, it involved inten­sive exper­i­men­ta­tion, and even the inven­tion of a new mea­sure­ment device: in this case, a sim­ple 3D-print­able “Ore­ome­ter” (seen in ani­mat­ed action above) that uses pen­nies and rub­ber bands.

With it the researchers applied “applied vary­ing degrees of torque and angu­lar rota­tion, not­ing the val­ues that suc­cess­ful­ly twist­ed each cook­ie apart,” writes MIT News’ Jen­nifer Chu. “In all, the team went through about 20 box­es of Ore­os, includ­ing reg­u­lar, Dou­ble Stuf, and Mega Stuf lev­els of fill­ing, and reg­u­lar, dark choco­late, and ‘gold­en’ wafer fla­vors. Sur­pris­ing­ly, they found that no mat­ter the amount of cream fill­ing or fla­vor, the cream almost always sep­a­rat­ed onto one wafer.”

Crys­tal Owens, a mechan­i­cal engi­neer­ing PhD can­di­date work­ing on this project, puts this down in large part to how Ore­os are made. “Videos of the man­u­fac­tur­ing process show that they put the first wafer down, then dis­pense a ball of cream onto that wafer before putting the sec­ond wafer on top. Appar­ent­ly that lit­tle time delay may make the cream stick bet­ter to the first wafer.” But oth­er phys­i­cal fac­tors also bear on the phe­nom­e­non as well, as doc­u­ment­ed in the paper Owens and her col­lab­o­ra­tors pub­lished ear­li­er this year in the jour­nal Physics of Flu­id. “We intro­duce Ore­ol­o­gy (/ɔriːˈɒlədʒi/), from the Nabis­co Oreo for “cook­ie” and the Greek rheo logia for ‘flow study,’ as the study of the flow and frac­ture of sand­wich cook­ies,” they write in its abstract. For a sci­en­tif­i­cal­ly inclined young­ster, one could hard­ly imag­ine a more com­pelling field.

Relat­ed con­tent:

Sci­ence & Cook­ing: Harvard’s Free Course on Mak­ing Cakes, Pael­la & Oth­er Deli­cious Food

Nor­man Rockwell’s Type­writ­ten Recipe for His Favorite Oat­meal Cook­ies

Dessert Recipes of Icon­ic Thinkers: Emi­ly Dickinson’s Coconut Cake, George Orwell’s Christ­mas Pud­ding, Alice B. Tok­las’ Hashish Fudge & More

Mak­ing Choco­late the Tra­di­tion­al Way, From Bean to Bar: A Short French Film

MIT Researchers 3D Print a Bridge Imag­ined by Leonar­do da Vin­ci in 1502— and Prove That It Actu­al­ly Works

Based in Seoul, Col­in Mar­shall writes and broad­casts on cities, lan­guage, and cul­ture. His projects include the Sub­stack newslet­ter Books on Cities, the book The State­less City: a Walk through 21st-Cen­tu­ry Los Ange­les and the video series The City in Cin­e­ma. Fol­low him on Twit­ter at @colinmarshall or on Face­book.