Image To determine the best method for cooking boiled eggs, J. Kenji López-Alt orchestrated a double-blind experiment at his restaurant, Wursthall, in San Mateo, Calif.CreditCreditPeter Prato for The New York Times Years ago, in an effort to answer a perennial question — what’s the best way to boil an egg? — I hatched a plan using the only method I know: lots and lots of testing. It was a multidecade endeavor. The series of tests I conducted variously as a kitchen monkey at Cook’s Illustrated magazine, as recipe czar at the website Serious Eats and in researching my cookbook produced good data, but none of it felt definitive. Further home experimentations (there have been weeks when my wife, Adri, begged me to stop serving egg salad for dinner) have left unanswered questions and conflicting results. Do older eggs really peel more easily? (The internet insists they do.) Can an ice bath prevent green yolks? Is there anything the Instant Pot can’t do better? I simply did not have enough data to say for certain. Ninety-six volunteers came through my restaurant, Wursthall, in San Mateo, Calif., in August to peel and taste more than 700 eggs, cooked with various methods, making this — as verified with a cursory search online — the largest-ever double-blind egg-boiling-and-peeling experiment in the history of the universe. (If anyone from Guinness is reading, I have pretty extensive documentation.) I have bad news: There is no way to guarantee eggs that peel 100 percent of the time. But if 87 percent or higher is a number you can work with, let’s crack on. First, let me share my idea of a perfect boiled egg: It should be tender throughout, even when fully hard-boiled. The white should not be rubbery, nor the yolk chalky or green. And above all, it should peel easily. There are few frustrations greater than watching a chunky divot of egg white dislodge itself as you claw clumsily at the shell. There are two stovetop cooking methods that allow preheating for a hot start, and produce eggs that are equally easy to peel: boiling and steaming. Moreover, blindfolded tasters confirmed that the whites were noticeably tougher (given the same internal yolk temperature). This makes sense, given the high cooking temperature achieved in a pressure cooker. Also not recommended: the briefly popular technique of baking eggs in their shells in a muffin tin. Some variables had little to no effect. Adding small amounts of vinegar, baking soda or salt to your water is pointless. None offer advantages for peeling, while at the extremes, vinegar and baking soda produce off-flavors and colors (ghostly blue egg whites!). The only difference between fridge-cold eggs and room temperature eggs is that room temperature eggs will cook about a minute faster. Turns out that age doesn’t make much of a difference either. Even eggs still warm from the hen’s body peeled just as easily as the most grizzled specimen. (Taste tests also showed that most folks could not tell the difference between backyard eggs and supermarket eggs, and those who could were split on which were better.) Pricking the fat end of an egg with a pushpin doesn’t affect how easily an egg peels, but it can prevent thin-shelled eggs from cracking under the pressure of gas expansion during boiling. It will also reduce the large dimple you often find at the fat end of the cooked egg, caused by the impression of an air pocket located there. Immediately dunking your cooked eggs in an ice bath will have a similar dimple-reducing effect, but it also makes them a little more difficult to peel. This result surprised me, as previous smaller-scale tests had suggested a slight advantage in peeling eggs that were iced; but when a mountain of new data doesn’t fit your previous hypothesis, you change your hypothesis. An ice bath also did not help reduce the incidence of the sulfurous green patina around overcooked egg yolks — eggs are so small that there is negligible carry-over cooking. If the yolk is green, it would have been green ice bath or no. Whether you use that information to change your everyday cooking, or perhaps just to volunteer unsolicited cooking tips to a perfectly capable brunch host, I hope you find something useful. Recipe: Perfectly Peelable Steam-Boiled Eggs | What to Do With All Those Boiled Eggs J. Kenji López-Alt is the author of “The Food Lab: Better Home Cooking Through Science” and the culinary adviser for the website Serious Eats. He is also the chef and co-owner of the restaurant Wursthall in San Mateo, Calif. His new column, about science and home cooking, will appear monthly.