Where Pantry’s expiry dates come from

When Pantry attaches “3 days” to the chicken and “6 weeks” to the eggs off the same scanned receipt, those numbers came from somewhere — and where they come from is the difference between a countdown worth planning dinner around and a decoration. So here is the sourcing, in the open, the same way every number on this site carries its source.

Published research first

The backbone is CSIRO’s refrigerated storage guide — poultry at three days, milk at five to seven, hard cheese at one to three months, eggs at three to six weeks. Where CSIRO publishes nothing — fresh produce and bakery, mostly — the figures come from Australian consumer food-safety guidance, Sustainability Victoria and the NSW Food Authority among them. The same dataset drives the reference table on this site and the app’s windows: one source of truth, published where anyone can check it.

Just as important is what happens where no source exists. It stays blank rather than getting invented — the reason our freezer guide refuses to reproduce the unsourced per-food freezer chart the rest of the internet keeps copying. A number nobody can trace is not data. It is decoration with a font.

The cautious end, every time

Published shelf life usually arrives as a range, and a range forces a choice. Pantry takes the cautious end, consistently — the home-fridge end, the end that assumes the door gets opened and the fridge is not a lab. A countdown that errs early costs you a day of flexibility. One that errs late costs you the food, and sometimes more than that. Between “cook it a day sooner than strictly needed” and “trusted the optimistic number,” the first is the only defensible default for an app whose entire job is being believed.

Per item, not per fridge

The core design rule: chicken and cheddar do not age alike, so the app does not pretend they do. Each line off a scanned receipt maps to its own window — no universal seven-day guess stamped across the basket. It is the difference between a list that tells you what to cook first and a list that just blinks at you.

The date on the packet still matters where it is a safety date. Use-by is a hard stop; best-before is a quality estimate — and an estimate is what a countdown is, which is why yours can overrule it. You confirm every list after a scan, and any date that looks wrong for the item in your hand is yours to change. The research sets the default; your kitchen sets the exceptions.

An estimate that admits it

None of this makes the countdown an oracle. A bag of spinach that spent a hot afternoon in the boot ages faster than any table predicts, and your nose outranks any number this site or the app will ever show you. What the sourcing buys is something narrower and more useful: a default good enough to plan dinners around, open about where it came from, and cautious in the only direction that never costs you a meal. That — multiplied across every item in the trolley, every week — is the whole product.