CBS News/ April 16, 2011, 9:42 AM

Decoding food expiration dates

It's a question millions of us try to answer every day: How long is food safe to eat after its sell-by date has passed?

On "The Early Show on Saturday Morning," dietitian Tanya Zuckerbrot, author of "The F-Factor Diet," shared some advice for this dietary dilemma and what the dates stamped on food products really mean.

Zuckerbrot explained the three most common dates are Sell-By Date, Use-By Date, and Expiration Date. But what do they mean?

Sell-By Date: Refers to the last day a retailer can display a product for sale; typically a food is safe to eat for 10 days after the Sell-by Date if refrigerated properly.

Use-By Date: Refers to the last day a product will maintain its optimum freshness, flavor, and texture. Beyond this date, the product begins to deteriorate although it is still edible.

Expiration Date: Means what it says - if you haven't used a product by this date, toss it.

Zuckerbrot pointed out a surprising fact: with the exception of baby food and infant formula, dating is not required by U.S. federal law.

So how do you know what is good and what is not safe to eat?

Zuckerbrot shared how these food products are labeled and how long it's safe to eat them:

Poultry and Meat

Meat and poultry typically have a Sell-By date. You should use or freeze your chicken within one to two days of purchasing and meat within three to five days of purchasing. Freezing your poultry and meat can make these proteins last anywhere from nine to 12 months. When freezing, it is important to make sure your poultry and meat is tightly wrapped in order to prevent it from freezer burn. Freezer burn does not make food dangerous to eat, but does damage the texture and taste.

Dairy and Eggs

Dairy and eggs typically have a Sell-By Date

Proper refrigeration (40? F or below) is vital to ensure the best possible shelf life of your dairy.

According to the Dairy Council of California, the shelf life of milk is affected by several factors, including how it is handled before and after it is purchased. When stored at 40 degrees Fahrenheit and not left out of the refrigerator for extended time periods, milk should last approximately five to seven days past the "sell by" date."

The type of cheese contributes to its shelf life. Soft cheese (cream cheese) will last up to two weeks, whereas a medium or hard cheese (cheddar) can last three to six months.

The Egg Safety Center reports that the dates on egg cartons are not food expiration dates, but guidelines. Raw eggs can stay good for approximately three to five weeks after the date of purchase as long as they are not cracked or damaged.

Baked Goods and Snack Foods

Baked goods and snacks typically have a Use-By Date.

Store-bought bread will typically last five to seven days at room temperature, but can last one to two weeks in the refrigerator. Fresh-baked bread do not contain preservatives, so they typically won't keep as long as commercially packaged breads.

If the date on your bread or snacks has expired, it does not mean they have not gone bad. In fact, once something something goes stale it means that it has been depleted of moisture, which makes it less likely to grow mold. Try storing it in a plastic bag for extended shelf life.

Snack foods contain preservatives in order to maintain shelf life.

Different types of snacks have varying expiration dates: Potato chips will last one month after expiration date. Crackers and pretzels can last up to three months. One of the longest lasting snacks is popcorn, which has a shelf life of one to two years.

There is a myth that Twinkies can last upward of 50 years. However, this is urban legend. Twinkies can last for a lengthy 25 days without packaging, because dairy products are not a part of the recipe. After 25 days, a Twinkie does not spoil, but loses some of its taste and flavor.


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18 Comments Add a Comment
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muraydog says:
What about openned jars of say, spagetti sauce? How long can they be in the refridgerator?
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muraydog says:
What about openned jars of say, spagetti sauce? How long can they be in the refridgerator?
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nosharia says:
It would have been helpful to also address the distinctions of "Shrink wrap" and "Vacuum sealed" or "Cry-o-vac" meat products. A food item that has been frozen by vacuum methodology lasts for much longer periods of time.
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are122 says:
I unfortunately opened a container of refridgerated chicken livers 8 days after the "sell by" date. The container "popped" splattering black slime in my face. The contents of the container looked like black tar mixed with snot...and smelled horrible. Wouldn't recommend this procedure to anyone...well, maybe ex-wife.
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erasmus111 replies:
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Ummmm....Chicken livers? That's sounds yikky anyways.

I'm sure your ex-wife feels the same. In fact, I think she would be laughing herself silly over this. : )
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Swann51 says:
One point of clarification, while there are no federal laws for what's referred to by trade as "Open Dating" or Uniform Dating, it is regulated at the State level.

http://www.fsis.usda.gov/factsheets/food_product_dating/index.asp

http://ts.nist.gov/WeightsAndMeasures/upload/14_IV_OpendateReg-06-H130-FINAL.pdf

and lots of dates on non-perishable, shelf-stable foods are more about quality than food safety.
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lampshade54 replies:
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I would like to expand that last point. Food dates have become a marketing tool to enable companies to sell more by convincing the public they indicate "quality." For example, Vinegar previously had a shelf life of seven years, but companies cut it down to a single year so it appeared fresher. By implementing all of these arbitrary dates, food manufacturers have instilled consumers with an obsession for freshness and quality, but can we really tell the difference. A study by Brian Wansink, named ABC World New's person of the week in 2007, and Alan Wright examined 36 participants' opinions towards yogurt dates. Although the participants rated the two yogurts ahead of the "best if used by date" much healthier and fresher than the later dated yogurt, what they didn't know was that all three yogurts were in fact 30 days ahead of the ebst if used by date. Obviously use common sense when eating food, but don't allow clever marketing to dictate your decisions. After all, wasted food accounts for more than a quarter fo total water consumption in the E.S and approximately 4% of total U.S oil consumption each year. According to the E.P.A discarded food is the largest component of municipal solid waste reaching landfills and incinerators. Everyone should form their own opinion and ignore Tanya's advice that use-by dates are a true "quality issue."
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erasmus111 says:
There are some foods that the expiration date is only good as long as it hasn't been opened. Like Mayonnaise. Once the Mayonnaise has been opened, it is only good for about 2 to 3 months. It depends on how long it has been left out of the fridge, and whether or not you have contaminated it with a dirty knife.

It is the same for cheese. Once it is opened, the date is then cancelled out. It can start getting moldy within a few weeks. Just depends on how you have handled it.
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senca67 replies:
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With moldy cheese I just cut off the mold and use it.
erasmus111 replies:
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by senca67 April 16, 2011 6:14 PM EDT
With moldy cheese I just cut off the mold and use it.


Did you read this, from page two?

"However, molds are filamentous (threadlike) and when a food shows mold growth on the surface it means that the root like threads have invaded the entire food."


I used to just cut off the mold too, but then I heard about this. The mold is always a lot further into the food and you don't see it.
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kenhamlett says:
I am very happy that most manufacturers now have easily readable dates. Once upon a time one had to have a secret decoder ring to understand the encrypted information. It makes life a lot easier to be certain of our food quality.
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cktirumalai says:
Thanks for clarification in this important matter of dates, particularly in regard to bread and milk. It helps me to know that refrigerated bread will keep longer. Some make things afresh and consume them soon after but most of us have to make do with at least some ready-made, store-bought items, though even here there is a choice between better and worse, as, for instance, with the kind of grain used, whether it is whole or "refined".
Candadai Tirumalai
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erasmus111 replies:
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I heard that if you keep bread in the fridge, it can actually get moldy faster because it makes the bread more moist.
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buzz122 says:
I have to strongly disagree with the on-air statement that beer has an expiration date of 4 months. That is not completely true. As long as bottled beer is kept out of direct sunlight it can be kept for many decades, granted the bottle or can is kept sealed. The only thing that can spoil a beer is an infection that is introduced due to bad sanitation practices at the brewery. Usually you would be able to tell if a beer has been infected, that it will taste off, sour, and/or not drinkable. But the chances a beer with a bad infection from a major brewery are more unlikely than catching salmonella from a door handle. Personally, i have had some very great beers that have been "aged" and in fact, those beers tend to taste better with all their taste profiles starting to mature only years later. In any case, thought i mention it.
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erasmus111 replies:
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Beer and soda do not last as long if kept in a fridge.
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