Cracking boiled eggs for Easter Wherever there are Orthodox Christians, there are brightly pigmented red boiled eggs for Easter. These are eaten throughout Eastern Europe and Greece. They should have been boiled yesterday - known as Red Thursday in Greece - ready for Easter breakfast. Red eggs look wonderfully exotic piled in a bowl and aren't hard to make using a traditional Russian onion-skin dye. Just save the skin in the fridge every time you use an onion for a week, then boil with 2 tbsp vinegar (any kind except balsamic) and a litre of water for half an hour. You then use this liquid to hard-boil the eggs as usual, topping up as necessary with more water. The tricky part is getting the shell red enough without overcooking them. Among the Orthodox, there are various Easter-egg-cracking ceremonies where you try to crack someone else's red egg before they crack yours - like conkers - which gives a sense of how rubbery red eggs can be. Cooks have always known that boiled eggs have a minuscule margin of error, but we now know far more about why. Tiny variations in the temperature inside the shell result in an egg that is either creamily perfect or grey and tough. Modernist Cuisine at Home, by Nathan Myrhvold and Maxime Bilet, which I would urge you to buy if it didn't cost £100, has an extraordinary two-page spread showing how the white and yolk change by degree. At 55°C, the egg looks raw: transparent white, gloopy yolk. Just five degrees hotter, at 60°C, the white is starting to gel. Somewhere between 62°C and 65°C, it becomes a perfect soft boiled egg, with a yolk prime for dipping. But seconds later, at 68°C, the yolk goes 'jammy' and by 70°C it is 'fudge-like', no good for soldiers. Modernist chefs have tried to use this new scientific knowledge to rethink egg cookery. Myrhvold and Bilet note that 'sunny-side up' eggs (fried to you and me) pose 'an inherent problem: the yolk and the white reach their ideal textures at different temperatures'. Their solution is to cook the yolk and white separately - using a sous-vide machine and an oven - then reassemble the parts. This takes 1¼ hours and 14 eggs to make just four servings. Not exactly a simple breakfast. For less ambitious cooks - I include myself here - I recommend the section on egg cookery in the delightful Cooking for Geeks, by Jeff Potter (O'Reilly Media, £26.99). Potter notes that there's a war of 'PC-versus-Mac proportions' between those who start their hard-boiled eggs in cold water and those who drop them straight into boiling water. The cold-start approach yields eggs that taste better, while the boiling-water approach yields eggs that are easier to peel. Potter has devised an ingenious 'shock and awe' method combining the best of both. You 'shock' the eggs for 30 seconds in boiling water before proceeding with the cold-water method, shaving two minutes off your normal timing. I tested three lots of eggs side by side and found that Potter's method really worked. The shells peeled off as cleanly as from the boiling-water eggs but the whites had the milkiness of the cold-water ones. Clever. By next Easter, I hope to find out if it works on red eggs, too.