There seems to be a bit of confusion over the use by dates and best before dates on packaged foods, writes Marjorie Harvey, founder and director of Australian Food Hygiene Services.
A use by date is predominantly on perishable foods –food that must be held under refrigeration at all times. A company cannot sell food past its best before date (nor have it in their store) hence why it is often “reduced for quick sale”. A product with a use by date “must” be sold and consumed on or before that date.
A best before date is more a quality date. A best before date on a product is generally a lower risk product that will most likely go stale before it is a food safety risk. Best before products may be OK to use for up to two years if stored according to the storage condition as listed on the label. Although other products may not keep that long, so you will need to ensure the texture such a mould or smell has not been compromised before you use it if kept for a longer time.
However, a lot of shelf stable products with a best before date can be held without refrigeration “until opened”. Such products could be canned foods, fruit juices, long life custard, milk and sauces, for example. Once these products are opened, they may need to be refrigerated and the best before date then becomes a use by date. This information is usually stated on the labels (but unfortunately in very small print)
We now have canned foods that may not have an expiry date at all (just a batch number) and can be held in a dry place for a long time if not swollen, dented or damaged. Generally, the label states to refrigerate after opening in a covered, non-metallic container –and use within a very short time. Some may be one day (e.g. tuna) or 3-5 days. Beetroot is usually a bit longer (7 days) on account of the higher acidic content. Some exported canned products do not state a revised use by date once opened, therefore I would still use the same guide to refrigerate in a lidded non-metallic container and use by three days to ensure safety.
Cryovac meats such as bacon need to be refrigerated at all times and used by the date on the package and also need to be used within three days once opened, unless the label states otherwise (the changed use by dates can also be in very small print). Some cryovac deli meats only have two days.
Many sauces have a best before date that doesn’t change, except it may state on the label to keep it refrigerated once opened.
It’s very important that you read the labels carefully as many products that once had a longer time to use, now may be compromised once opened if not redated. It is always a good idea to add the revised use by date as you may forget when you opened it.