Eggs

Yolk is rich, buttery, almost savoury-sweet. White is clean and barely-there on its own — basically protein and water until heat or whisking gives it a job to do.

One of the most complete proteins going — your body uses nearly all of it. The white is mostly water and protein, with virtually no fat. The yolk carries most of the fat along with many of the egg's vitamins and minerals — B12 for your nerves, choline for your brain, riboflavin for energy, selenium, vitamin D and the fat-soluble vitamins A, E and K. Bin the yolk and you bin the nutrition. A whole egg is roughly 6g protein for about 70 calories.

Look for intact shells and a best-before date that suits your plans. Give the carton a gentle shake — a loud sloshing egg is an old one. Yolk colour comes mainly from the hen's diet. A deeper orange yolk does not automatically mean the egg is free-range, more nutritious or better quality.

In Australia, refrigerate eggs as soon as you get them home. Keep them in their original carton on a middle shelf rather than in the fridge door, where the temperature changes every time it opens. Once chilled, keep them chilled. Store them pointy end down — yolk stays centred, air sac stays put at the top. Do not wash them — the shell has a natural coating that keeps bacteria out. The float test: put an egg in a glass of water. Sinks and lies flat = fresh. Stands upright = a week or two old, still fine. Floats = past it, bin it.

Freezing works well, but never freeze whole eggs in their shells — the shell cracks and the expanding white makes a mess. For whole eggs, crack them into a bowl, whisk gently to blend white and yolk, then pour into an ice-cube tray. Freeze in measured portions and label how many eggs are in each portion. Whites freeze almost perfectly and keep for months. Yolks can turn gummy after freezing, so beat in a pinch of salt for savoury use, or a pinch of sugar if you will use them for baking — that stops them setting like rubber. Defrost cubes overnight in the fridge and use within 24 hours. Frozen eggs are best for cooking and baking where they are mixed in; they do not poach or fry cleanly afterwards.

Fresher isn't always better. For boiled eggs you want them about a week old — the membrane separates slightly from the shell, making them easier to peel. Ultra-fresh eggs are a nightmare to peel.

When you crack an egg, the white should hold close to the yolk in a tight oval. A runny watery white that spreads everywhere is an old egg.

Boiled, fried, poached, scrambled, baked into everything, whisked into mayo and hollandaise, beaten into custards, folded into sponges. The white whips into meringue because the proteins unravel and trap air. The yolk emulsifies oil and water thanks to lecithin. Real burgers do not need egg — if you are binding mince with egg and breadcrumbs you are making a rissole or a patty, which is a different beast and not a worse one, just be honest about what it is.

The printed code on every egg in the UK and EU tells you exactly how the hen lived. First digit: 0 = organic, 1 = free-range, 2 = barn, 3 = caged. The rest is country and farm.

Can you taste the difference? Not reliably. Free-range and barn-raised eggs do not automatically taste different. Any noticeable flavour difference comes mainly from what the hens are fed, rather than whether they are kept free-range or barn-raised.