Expiration, Use-by, and Sell-by Dates

Part 1: Expiration dating is not federally required on all products

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The twentieth century ushered in the age of packaged foods, making use of preservatives and innovative packaging to lengthen the shelf-life of many foods. Most packaged foods include some type of expiration, sell-by or use-by date imprinted on the container. Figuring out the intent of that date is not always an easy matter. Even the general industry terms for it,open-dating and closed dating, raise questions.

You may be surprised to learn that dating is not required by US federal law, with the exception of infant formula and baby foods which must be withdrawn by their expiration date. For all other foods, except dairy products in some states, freshness dating is strictly voluntary on the part of manufacturers. To further shake your confidence, stores are not legally required to remove outdated products from their shelves. So, it's the old caveat even when it comes to food: Buyer beware and always read the label.

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In order to ensure you are getting the freshest product, it is necessary to scrutinize packaging and purchase the items with the most recent dating. Although most markets are vigilant about rotating stock, some are not. In a properly stocked store, the freshest items will be at the back of the shelf or underneath older items.

This helps the store move older merchandise and protects manufacturers from potential liability claims.


So what do the terms mean to consumers?

Expiration date terminology 

These terms all apply to unopened products.

•  Best if used by and use-by date: With emphasis on thebest qualifier in this term, it means the product should retain maximum freshness, flavor and texture if used by this date. It is not a purchase-by or safety date. Beyond this date, the product begins to deteriorate, although it may still be edible.

•  Expiration date: If you haven't used the product by this date, toss it out.

Other dating terms are used as a basic guideline, but this one means what it says.

•  Sell-by or pull-by date: This date is used by manufacturers to tell grocers when to remove their product from the shelves, but there is generally still some leeway for home usage. For example, milk often has a sell-by date, but the milk will usually still be good for at least a week beyond that date if properly refrigerated.

•  Guaranteed fresh: This date is often used for perishable baked goods. Beyond this date, freshness is no longer guaranteed although it may still be edible.

•  Pack date: This is the date the item was packed, most-used on canned and boxed goods. It is usually in the form of an encrypted code not easy to decipher. It may be coded by month (M), day (D), and year (Y), such as YYMMDD or MMDDYY. Or it may be coded using Julian (JJJ) numbers, where January 1 would be 001 and December 31 would be 365.

In even more convoluted coding, letters A through M (omitting the letter I) are often assigned to the months, with A being January and M being December, plus a numeric day, either preceded or followed by the numeric year.

Food storage tips & hints 
•  Once opened, many of the dates become obsolete since the contents now become perishable. It is advisable to use products as quickly as possible after opening. 

•  Be sure to refrigerate leftovers in a covered container (not a can) and use within 3 to 5 days.

•  Some canned goods (such as condiments and pickled items) will still retain some longevity if refrigerated. Most condiments will have a warning to refrigerate after opening if necessary, so check the packaging carefully.

•  When buying foods, always check the expiration date. Select the date farthest in the future for optimum shelf-life.

•  Fresher packages may be at the rear or buried. Depending on how quickly you will be using an item, it may be worth digging out the newer product, but be sure to re-stack for the grocer.

•  Take a tip from grocers and rotate your stock at home. Rather than trying to decipher cryptic codes on cans, use a marker to write the purchase date on cans and packaged foods to help you judge the age.

•  Regardless of the expiration date, do not take a chance on cans that are bulging or oozing from the seam. Dented cans should also be avoided.

•  Many baking mixes contain dehydrated fats which can become rancid with time or leaveners that may lose their potency. Check the date.

•  Optimum storage temperature for canned goods is 65 degrees F. Higher storage temperatures can reduce shelf-life by up to 50 percent.

•  Most canned goods can be stored up to 1 year under optimum temperature. Citrus fruits, fruit juices, pickles, peppers, sauerkraut, green beans, asparagus, beets, and all tomato products should be used within 6 months. If summer heat brings your kitchen temperature to 75 degrees F. or above, even for a short time period, cut those storage times in half.

•  Canned foods should never be frozen. The expansion can split the seams of the can or break the glass container. 

•  In general, foods canned in glass have a longer shelf-life. However, they must be stored in the dark since light can accelerate some natural chemical reactions.

•  Examine cellophane, plastic, and box packages to be sure they are not punctured or torn. Once the seal is penetrated, the integrity of the contents is compromised.

•  Get your food home quickly from the store and into proper storage.

•  The bottom line: Trust your eyes and nose. If it looks bad and/or smells bad, toss it out.