How Long to Soft-Boil an Egg

The timer hits 6 minutes 30 seconds. Lift the egg from the boiling water, drop it into the ice bath, and crack the shell at the wide end. The white is set, no snotty layer clinging to the shell. The yolk stays liquid, ready to soak into toast or run across a salad. That is the soft-boiled egg you came for, and the time that gets it right for a large egg straight from the refrigerator.

You need a single, reliable soft boiled egg time that works every time. The answer is 6 minutes 30 seconds in boiling water for a large USDA egg. That number comes from Serious Eats tested method, not from a generic chart. Use it as your baseline, then adjust for the variables that actually matter: egg size, starting temperature, and altitude.

What You Need

A pot large enough to hold the eggs in a single layer. Water deep enough to cover them by at least one inch. A slotted spoon or wire basket. A bowl of ice water. A timer you can set to seconds.

The Method

Bring the water to a full, rolling boil. Lower the egg gently with the spoon to avoid cracking. Start the timer. For a large egg straight from the fridge, set it for 6 minutes 30 seconds. Pull the egg from the boiling water and plunge it into the ice bath. Leave it there for at least 30 seconds, then peel.

Why the Ice Bath Matters

The ice water shock stops the cooking instantly. Without it, the residual heat in the shell continues to cook the yolk, turning a runny yolk into a jammy one. Serious Eats tests confirmed that a 30-second ice bath locks in the doneness. It also improves peelability by contracting the egg away from the shell membrane.

Egg Size Adjustments

A jumbo USDA egg needs about 30 seconds more, so set the timer to 7 minutes. A medium egg needs about 30 seconds less, so set it for 6 minutes. The white sets at 144-162°F and the yolk at 158-170°F, so the difference in thermal mass between a 1.25-ounce peewee and a 2.5-ounce jumbo changes the time.

Altitude Adjustments

Water boils at 212°F at sea level. At 5000 feet it boils at 202°F, so the water is cooler and the egg takes longer to cook. Add 1 minute per 3000 feet of elevation. At 5000 feet, cook a large egg for 7 minutes 30 seconds. This is a starting point, not a formula. Test one egg first, then adjust. The Colorado State University Extension publishes high-altitude guidance that confirms this range.

The yolk proteins need 158-170°F to set. The white proteins set at a lower range, 144-162°F. That gap is why a soft-boiled egg works. The white reaches its setting temperature first, while the yolk is still liquid. The trick is to hold the egg at the right temperature long enough for the white to set without pushing the yolk past 158°F.

The failure case is overcooking. If you leave the egg in hot water too long, the yolk temperature climbs past 158°F and the yolk sets. The white goes rubbery and a green ring of iron sulfide forms between the yolk and white. That ring is harmless but it means you overcooked the egg.

The three-minute window from 3 to 6 minutes is where the white sets but the yolk stays runny. At 3 minutes the white is barely set, with a snotty layer near the yolk. At 4 minutes 30 seconds the white is mostly set but still a little loose. At 6 minutes the white is fully set and the yolk is still liquid. At 6 minutes 30 seconds the white is firm and the yolk is runny, which is the standard for a dippy egg.

A soft-boiled egg is cooked in the shell in boiling water. A coddled egg is cooked in a small, lidded dish in a water bath, and the white spreads into a cup shape before setting. A poached egg is cooked out of the shell in simmering water. The differences are structural: the soft-boiled egg keeps its round shape and the white sets against the shell, while the poached egg loses its shape and the white sets against the water.

A ramen egg, or ajitsuke tamago, is a soft-boiled egg that is then marinated in soy sauce and mirin. The boiling time is the same, but the egg is peeled first and then submerged in the marinade for 4 to 24 hours. Just One Cookbook uses a 7-minute timing for a large egg straight from the fridge, then marinates it.

Tap the wide end of the egg against the counter. The air sac at that end creates a pocket that makes the first crack easier. Peel the shell from the opening, working under running cold water to wash away shell fragments. The ice water shock already loosened the membrane, so the shell should lift away cleanly.

If the shell sticks, the egg is too fresh. Egg age matters. Fresh eggs have an albumen pH around 7.5. After 7 to 10 days the pH rises to about 9.3, which makes the white separate from the membrane and peel much more easily. A week-old egg peels cleanly. A day-old egg is a disaster. Buy eggs for boiling at least a week before you plan to cook them.

A runny yolk egg means the yolk did not reach 158°F. That temperature is the threshold where yolk proteins set, but it is also the temperature that kills Salmonella bacteria. The FDA and USDA FSIS advise that vulnerable groups, children, the elderly, pregnant women, and anyone with a compromised immune system, should avoid runny yolks. The guidance is clear: cook eggs until both the yolk and white are firm.

If you are not in a vulnerable group, the risk from a soft-boiled egg from a refrigerated, clean, uncracked egg is low. The FDA Food Code 2022 edition recommends that commercial kitchens serve only fully cooked eggs to vulnerable populations. At home, you make that call. The safest option for anyone who is pregnant or immunocompromised is a hard-cooked egg where the yolk reaches 170°F.