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Best Before Date

The idea of having "best before" dates on food is a first attempt to quantify the level of freshness or staleness of food. This is a good idea, as you can tell if the food is "in date" or not. However, best before dates have produced a strange misconception which is surprisingly widespread, in which food is believed to "expire" at some exact point. Let's examine the reality first and then look at how best before dates try to approximate to that:

First Experiment:

Take a banana and leave it in a fruit bowl and see what happens over the next few days and weeks. If you bought the banana on day 1, you would probably find it reasonable to eat it on any one of the ten days after that. If you didn't eat the banana, then after about day 20, it would perhaps not be so nice, but it would still be edible. With hindsight you might say that the banana would have been best before day 12, or something like that.


The important thing about this experiment is that there was no time at which the banana became inedible. Even if officialdom has stuck a label on the fruit with a date giving a precise expiry time, it would not mean you would come to any harm eating the banana if it was after that date.

Second illustrative experiment:

The same kind of idea as with the first experiment with the banana, but this time with a packet of biscuits. This has a "best before" date on it, and it's going to stay fresh longer than the banana. But as that day approaches, nothing significant changes. The biscuits were ok after the date. Now supposing you added a fresh banana ten days before the biscuits were alleged to expire. A few days after the theoretical expiry date of both food items, it's clear to see that if someone doesn't eat the banana soon it will be too late, whereas the biscuits will most likely be ok for another month, or several months. Although both things had the same actual date, the reality was that the situations were not the same.


Different types of food goes off at different rates. It's not a simple "expiry date" but more that there's a time factor in each food type.

The reality:

Food has a START DATE when it was made, and a TIME FACTOR, more like the weight of a pendulum, or a half life, than a "this food item will self-destruct in [n] days".

The misconception:

Some people really do believe that food self-destructs at a precise time. Shops are desperate to sell food before the accursed time comes, for fear of being legalistically persecuted for selling food that was "out of date". This is silly, and besides being irrational it's also wasteful. With half of the world starving it's wrong to waste food. Do not waste food!

Common Sense:

It's best to use some common sense. You shouldn't eat shellfish that's very old, but you won't come to much harm eating biscuits that have gone a bit soft. Even with meat, which you might think would be foolish to eat if it's "bad", there is a technique where, within reason, you can declare a piece of meat to be "game meat", which according to the connoisseurs, is supposed to be left to go bad before eating it, as it improves the flavour! Generally, food that's cooked well at a very high temperature for slightly longer than recommended, is most likely to be ok.

It's different for different people. Some people can eat food that's quite clearly bad without coming to any harm, but some people are more sensitive to problems with the food. I have found by experiment that I can eat most foods well past the official sell-by date. But, I can't eat anything with wheat in it at all, regardless of how fresh it is!

"Best Before" dates are a first approximation to being able to label food and have an idea on how fresh it is. But they should be a guideline, not an absolute. Also, when the situation is revised, it should be possible to go for a start date and time factor, which would be better.

Extreme after best-before successes: I have found that Whitworths (moisturised and ready to eat) Apricots, best before May 1986, were perfectly edible and tasty in June 2010. Cans of beans (from Kwik-Save) best before 1996, were OK in 2009 (apart from the exception of cans that had swollen up). Also, cans of bread, best before 2000, were OK in 2010. Canned food keeps for years. It used to keep for decades! I've eaten war-time Condensed Milk and it was good.

Please don't write in and tell me it's lethally dangerous to eat a can of beans that's one day past the "Best Before" date! Try the banana experiment and see for yourself that food keeps a lot longer than it rated to. You may be surprised to find that a banana, even after the skin has gone black and it's obvious to any fool that it's gone BAD, is worth peeling to find it's perfectly ok inside!

Other vaguely relevant pages: Food , Misconceptions , Don't Waste Food , and the conjuring trick with the selective baddening of a banana