How to Make Perfect Poached Eggs, According to Science

We’ve all been there. Cursing ourselves as freshly cracked eggs twirl in hot bubbling water. Some yolks escape, while others form weird tadpole-like tails of frayed egg whites. Indeed, you often need to crack a few eggs to get a decent poached egg. To make poached eggs, generally speaking, you bring a large pot of water to a simmer and gently lower eggs that have been cracked in a separate bowl. A number of things can go wrong with this method, though. The yolk can break because of the turbulent water, the loose whites can form all sorts of weird shapes, the egg can stick to the bottom of the pan, and you can easily over- or undercook your egg. It’s a solid egg-poaching method in a pinch, but not foolproof by any means. The wonders of low-temperature cooking (similar to sous vide but not quite the same) are the answer to our poaching prayers. Low-temperature cooking is a technique popular among chefs that I first learned while working in fancy Manhattan restaurants. We’d drop dozens of eggs (still in the shell) into a temperature-controlled water bath (using an immersion circulator to regulate the temperature) and then go to family meal. By the time we got back, all the eggs were perfectly poached and just needed to be cracked open.Understanding the science behind cooking eggs will allows you to manipulate them to your desired results. So let’s first breakdown what an egg is and how heat affects it. According to food-science overlord Harold McGee*, the egg white makes up almost two thirds of an egg’s total weight, while the yolk is the other third. The white is comprised of mostly water (almost 90 percent) and contains two proteins—ovalbumin and ovotransferrin—that play a crucial role when it comes to cooking. The rest of the white is mainly small quantities of other proteins, minerals, and vitamins.The two main proteins begin to coagulate at different temperatures. Ovotransferrin will begin to set around 145°F and will be fully set at 150°F. Ovalbumin won’t coagulate until 180°F, at which point it will form the firm white gel that you see when you hard-boil eggs.The yolk, compared to the watery white, is very nutritionally dense. It’s mostly made up of lipids, vitamins, protein, and lecithin. The yolk begins to set at yet a third temperature: It will start to coagulate around 150°F and will be fully gelled at 158°F.So, given all that, it doesn’t really make sense to cook your poached eggs in water simmering between 180 and 200°F, does it? But that’s what most people do. By cooking your eggs in water that is the same temperature as your desired internal temperature, you eliminate the chance of overcooking. The downside is that it will take longer for the eggs to come up to temperature, 45 minutes to an hour.  For the record, you do not need an immersion circulator for this. Since you are only cooking for a short amount of time, simply bring a big pot of water (with a lid) to the desired temperature and have a small pot of simmering water nearby in case the temperature drops a couple degrees. It’s helpful to use a cast iron dutch oven, or a similarly heavy pot to help retain the heat, otherwise you’ll have to add hot water more frequently. Or, you can use a beer cooler (seriously).It’s harder to cook to an exact degree without an immersion circulator, so I tested this out with wiggle room of a few degrees. I cooked eggs at three different temperature ranges, 140 to 143°F, 144 to 147°F, and 148 to 151°F for 60 minutes. I used a large dutch oven with a lid and had to add a little hot water every 20 to 25 minutes.Call me old fashioned, but I like my whites a little more set, and the yolk a bit fudgy, so I’m in the 144 to 147°F camp. But if you like your yolks more runny, go for 140 to 143°F. As you can see in the 148 to 150°F test, the yolk has gelled too much.The window for the proper doneness (barely set, tender whites, and warm, runny yolk) can be obnoxiously small. But knowing some background egg science and thermodynamics, we can open up that window to full blast. By going low and slow, we eliminate the potential for overcooking, because the egg temperature cannot surpass the temperature of the water bath. *Egg facts courtesy of Harold McGee’s On Food and Cooking.Foolproof Low and Slow Poached Eggs