If you want an in-depth analysis of how heating eggs causes them to transform from a liquid to a solid then your best bet is to dive into Harold McGee’s treatise McGee on Food and Cooking: An Encyclopaedia of Kitchen Science, History and Culture. The short answer is that proteins bond more tightly to each other as the temperature is increased. The key is knowing when to stop to achieve a delicious creamy semi-solid rather than a rubbery, watery mess.
For several years, this ‘perfect’ egg has been popping up on menus everywhere from high-end London restaurants to suburban Sydney cafes, keeping food bloggers and magazine columnists busy. Chefs around the world love this egg for its maximum-impact, minimum-effort nature. This precise cooking method achieves a perfectly creamy result every time and in the high-pressure environment of restaurants consistency is everything. No longer relegated to breakfast, this soft poached egg is taking pride of place on salads, atop grain bowls, in soups and garnishing vegetable side dishes.
What do I need to know?
First of all, ignore the phrase “boiling an egg”. Whether you want soft yolks or a fully cooked yolk, eggs shouldn’t be taken anywhere near 100 degrees celsius, or boiling point. Some recipes recommend one minute per gram as a cooking time while others say a minimum 45 minutes to a maximum of two hours. Either way, this is more a weekend brunch than a quick breakfast before work.
The key to the whole deal is maintaining a precise temperature. Many kitchen thermometers struggle with the accuracy required for this but luckily for us, we spent more than we should have on a home brew system. It turns out we can also use this as an immersion circulator cooking system (often called a sous vide) to cook at a low and accurate temperature for set periods of time. You could try this at home with a pot of water and a thermometer, but it’ll probably be a bit hit and miss maintaining the correct temperature of the water.
As a rough guide, anything below 57 degrees is raw and I can’t recommend it. At 60 degrees the egg yolk and white are barely set and won’t hold their shape at all. At around 63 degrees the egg yolk firms to a point that it can be cut while the whites are still soft and custard-like. Between 63 and 65 degrees is the perfect stage for rich, thick yolks and quivering but not too runny whites. This is where you want to be. Above 65 degrees and you’re heading in standard soft-boiled egg territory like your mum would make you as a kid. Anything above 74 degrees is hard boiled and if you go any higher than this you might as well eat your spatula instead.
Are they worth the effort? Yes yes yes. As long as you have the time and the inclination, these slow cooked, soft poached eggs will reward your effort. Bear in mind, both flavour and texture are crucial so start with a good quality fresh product and you’ll never look at the humble egg the same way again.