Those of you who have joined us since we updated the Topaz menu in March will have noticed an interesting new addition, namely a ‘deconstructed’ Carbonara, featuring Pata Negra ham, Parmesan cheese and a 62° egg. It’s absolutely delicious, but what exactly is a 62° egg, and why are they appearing on more and more menus?
Eggs are one of the greatest gastronomic gifts there are, which is probably why the Catholic Church long ago banned their consumption for the 40-day Lent period when good Christians are supposed to abstain from eating the things they love. This is how the tradition of gifting brightly coloured eggs at Easter evolved, manifested today in delicious chocolate Easter eggs.
But if you Google “how to cook the perfect egg” you will have a nice sampling of 2,360,000 hits to choose from, which should occupy an afternoon or two as you diligently test each one. It turns out that trying to achieve an evenly cooked egg, with a dense, creamy, almost custardy yolk and smooth white that is neither rubbery nor a mushy mess is easier said than done.
But there is a way, and that is by cooking your egg ‘low and slow’, at 62° to be precise, for around 45 minutes. This is because 62° is the temperature at which the proteins in the white cook while the yolk (containing more fat and protein) requires a temperature of 68° to achieve the same effect. So while the lower temperature allows the white to cook through, it won’t overdo it while the yellow yoke transforms into a thick, creamy, delicious core. Meanwhile, the white develops a sort of ghostly, opaque aspect yet is dense enough to be cut with a spoon. This is how we serve it in our new Carbonara, so while it may look slightly different from any egg you may have seen before, we can promise that it will taste different too, divinely so.
The long cooking of eggs is not a new thing. The Japanese have been slow-cooking eggs in thermal springs for centuries to create onsen tomago, an egg with a soft, silky yolk and delicate, milky white. In the Middle East, ‘hamine’ eggs are simmered overnight in their shells together with oil and onions whose flavours permeate the proteins inside. In Oeufs à la Constantinopolitaine (1925), one recipe calls for cooking eggs in their shells in a mixture of olive oil and Turkish coffee for 12 hours. The mixture eventually penetrates the shell, turning the white amber and the yolks orange and delivering a chestnut flavour.
If you don’t have time to be cooking your eggs for half the morning, or have a thermal spring next door, it is possible to achieve similar effects at home according to the authors of Ideas in Food — Great Recipes and Why They Work (2010). After much trial and error, they formulated the 13-Minute Onsen Egg, which should give ‘tender, just cooked whites paired with warm, liquid yolks’. Another advantage of cooking this way is that you can also cook the eggs in advance and then warm them when needed. You will need a thermometer.
Heat a pot of water to 75°C, lower your eggs into the water and cook for 13 minutes*. Meanwhile, prepare an ice bath and transfer the eggs into the bath to cool once the 13 minutes are up. Crack the eggs gently into a shallow bowl. The thin white material (the bit that goes flat when you crack a fresh egg into a frying pan) will fall away leaving the perfectly cooked firm white and yolk ready to serve.
Cooked this way, the eggs can be kept for up to two days in the fridge. To warm them up again, place the eggs in a pot of 60°C water for 10 minutes to warm them through.
*As the authors of the book are American, we assume that the eggs are cooked straight from the fridge as all commercially sold American eggs must be refrigerated (as is also the case for Japanese, Australian and Scandinavian eggs). This is not usually necessary in the rest of the world.