SCADOHow long food lasts after opening
Last updated: 10 June 2026
The printed date assumes the pack is unopened. The moment you open it, that date stops being a reliable guide and a shorter "use within X days of opening" window takes over. The useful thing is to remember when you opened something - and follow the instruction on the label.
Why opening changes everything
EFSA explains that once a pack is opened, contamination can get in through the air, dripping liquids and your hands or utensils, and the protection of vacuum or modified-atmosphere packaging is lost. A separate, usually shorter "secondary shelf life" then applies.
So the rule after opening is simple: follow the manufacturer instruction, such as "keep refrigerated and use within X days of opening". That line takes precedence over the original printed date.
Typical windows once opened
These are guidelines, not guarantees - they vary by product, processing and how cold and quickly you stored the food. Opened fresh milk: about 2-3 days (Altroconsumo); USDA FoodKeeper guidance is more generous at around 5-7 days. UHT milk still needs refrigerating once opened.
Opened deli meats and cold cuts: roughly 3-5 days refrigerated, and they are a listeria-risk category, so treat them with extra care. Opened jarred pasta or tomato sauce: about 5-7 days with the lid tightly sealed - discard the whole jar at the first sign of mould.
Cans must never be stored opened: the UK FSA says to empty the contents into a covered container and refrigerate. Opened canned fish should be eaten quickly (histamine risk). Cooked leftovers: cool and refrigerate within 1-2 hours, then eat within about 2 days or freeze (the UK FSA gives 48 hours; the more generous USDA figure is 3-4 days).
Keep the fridge cold
Every figure above assumes a cold fridge. Keep it at 5C or below (UK FSA; the US equivalent is 4C / 40F). An opened food in a warm fridge spoils faster than any printed window suggests, so getting chilled food home and into the fridge quickly genuinely matters.
A note on safety
This is general information, not food-safety advice. The on-pack instruction and the use-by date always win over any general figure here. Never eat a food past its use-by date and never rely on look, smell or taste for use-by foods. Any mould, off odour, sliminess or bulging packaging means discard it - when in doubt, throw it out. Vulnerable groups should be extra cautious. SCADO is an organizational aid: it does not test food or decide what is safe, it only reminds you of the open-date you set.
When you tap "mark as opened" in SCADO, it records the date and sets a shorter open-deadline for that item, then surfaces it before the window runs out - so an opened jar is not forgotten at the back of the fridge. SCADO ->