How long do prawns last in the fridge?
Prawns bought on Christmas Eve are a two-day item. CSIRO’s refrigerated-storage guide gives crustaceans and molluscs — prawns, crabs, lobster, oysters, mussels — two days in the fridge, one day less than fish and the shortest window of anything in a Christmas shop. Bought on the twenty-fourth, they need to be eaten by the twenty-sixth. Boxing Day is the last day, not a spare one.
Two days, raw or cooked
CSIRO gives two days as a single figure, not a range, so there is no cautious end to take. Two is the number. Its row does not split raw from cooked either, and this site does not try to. Cooked prawns from the fishmonger are on the same two-day clock as green ones, and two days is shorter than any other rule that could apply to them, including the three days for cooked leftovers, so it is the one to use.
How long do oysters last in the fridge?
Two days, on the same CSIRO line as prawns. Oysters, mussels and other molluscs share the crustaceans row, and they share its reason: seafood is among the most spoilage-prone food that goes in a fridge, and shellfish is the most spoilage-prone seafood. Keep them cold from the shop to the plate and eat them inside the two days. Any that smell wrong when opened are done, whatever the day.
The coldest shelf, not the door
CSIRO’s refrigeration advice singles seafood out by name: store items that are quite susceptible to spoilage in the coldest part of the refrigerator. In a home fridge that is the back of the bottom shelf. The door is the warmest place in the fridge, and a bag of prawns in it on a hot December afternoon is spending its two days faster than the table assumes. The same arithmetic that makes a summer car boot risky applies to a warm fridge door.
Christmas Day counts against the two days
A platter of prawns on the table through a long lunch is in the 5°C-to-60°C danger zone the whole time it sits there, and the NSW Food Authority’s two-hour/four-hour rule is cumulative across the day. Prawns that sat out for three hours cannot go back in the fridge for tomorrow. They are eaten today or they are done. Put out what will be eaten in the next hour and keep the rest on ice in the fridge, in shifts, rather than the whole kilo at once.
Signs to trust
Fresh prawns smell of the sea and not much else. A strong ammonia smell is the sign to trust: they are done, on day one or day three. A slimy feel on the shells says the same thing. Colour on its own is not a reliable guide, so trust the nose over the look.
Where Pantry closes the gap
Two days is a window that closes inside a public holiday, in a fridge fuller than it is any other week of the year, with a household that is half guests. The kilo of prawns bought on Christmas Eve for a lunch that used most of it is the classic case: the rest goes to the back of a crowded shelf on the twenty-fifth and turns up on the twenty-eighth. Two days, run out under everything else.
Pantry is built for exactly that week. The Christmas Eve receipt dates the prawns the day they came home, with two days on the clock, on a list every phone in the house can see. On Boxing Day morning the digest says today, in plain words, before the fridge door is opened. And the ham on its two-week clock, and the fish on its three-day one, sit on the same list with their own numbers, so the fullest fridge of the year is a list rather than a guess. The waitlist is where to be when it ships, in time for next Christmas if not this one.