Some Shelf Life Info, General and Specific (Spirits, Defrosted Veggies, Green Tea, and More)

LiquorBecause the name of our website is Shelf Life Advice, we get a lot of questions asking for--you guessed it—shelf life advice. Below is some general information about shelf life and expiration dates, followed by answers to questions about the shelf life of specific products visitors to our site have asked about.   


Some General Shelf Life Tips


1) The use-by dates on food are a guide to quality.  They give you the last date that the product is at its best. They are NOT about safety. If a properly refrigerated edible item smells and looks fine, it’s probably safe to eat.  (For more info on food safety, click here.)


2) The use-by dates on products refer to the unopened product.  So how do you know how long it will last once it’s opened?  On the package, write the date you opened it.  Then, look up the item up on our site by using the search box.  You should find the answer to your question. 


3) Many shelf-stable or semi-perishable foods will last longer if they’re refrigerated (for example, apples). 


4) For extending shelf life, your freezer is probably your best friend-- if the product is well-wrapped in plastic (not aluminum foil, which can develop small holes) to prevent freezer burn.  Note: freezer burn is also accelerated by too much temperature fluctuation, caused by frequent opening and closing the freezer door. Who needs a breadbox?  Bread will last longer if kept frozen (double-wrapped and/or wrapped in a freezer plastic bag. (Once taken out of the freezer, a slice will defrost in minutes; rolls or a loaf can be quickly defrosted in the microwave.) 


5) Many shelf life problems can be avoided by good organization.  An overcrowded refrigerator results in some foods getting pushed to the back, not to be seen again until they’re stale or covered with mold.  If you put the latest canned goods you bought in the front of the shelf, you may not get to the ones in the back until they’re long past their expiration date.


FAQs on Liquor, Defrosted Veggies, and More


Does hard liquor really remain good forever—unopened or opened?


Forever is a really long time; experts on alcohol seem to prefer the word “indefinitely.”  If you’ve inherited your parents’ liquor collection, and you know most of those open bottles had been sitting on their shelves for years, take them home to drink or serve anyway.  Here’s reassurance from food scientist Denise Gardner: “Alcoholic beverages like bourbon, tequila, or rum can pretty much remain opened for years.  I’ve drunk gin that had been left open for several years.  There was nothing growing in it, and it tasted the same as if it came from an unopened bottle.” Some open liquor may lose a little flavor over a long period of time, but the change will probably be undetectable to most drinkers.   


Final proof (excuse the pun) of the longevity of spirits:  When Frank Sinatra, at age 50, married a 20-year-old, his pal Dean Martin said, “I’ve got scotch older than Mia Farrow.” 


Now you know why there’s no expiration date on most bottles of liquor.


Gardner recommends storing spirits in a dark, dry place.  “Some people like storing them in the freezer before or after they are opened, but I believe this is more for enjoyment of something cold.”


By the way, distilled liquor doesn’t age in the bottle.  It won’t taste any better if you keep it on your shelf for 5 years before pouring it.


For more information about spirits, click here.


How long can I keep liqueurs, those with or without dairy (cream or egg) in them? 


Let’s begin with the nondairy ones: says that, because liqueurs contain sugar and other ingredients that can spoil, they are more “temperamental” than spirits such as brandy, tequila, gin, rum, vodka, and whiskey.  Still, most open (but tightly-closed) bottles will last for months and perhaps for years, depending on the alcohol and preservative content. Open bottles may lose some sensory characteristics due to exposure to air, but small changes may be undetectable to most drinkers.  You may want to discard a bottle of liqueur or taste a drop or two to check quality if you see discoloration or curdling.


Here’s what has to say about liqueurs containing dairy: “Cream liqueurs, those that contain dairy, cream or egg, are a different story and should be discarded after 18 months or so.  [Some may have expiration dates on them.] Liqueurs like Bailey's Irish Cream, Advocaat and Amarula should be consumed within a year of opening, although some of their cheaper creamy cousins will most likely deteriorate faster. Even in unopened bottles, these liqueurs will spoil and be undrinkable after a year and a half or more. It is unnecessary to refrigerate cream liqueurs, but it can't hurt either.”  As they get old, the likely outcome is lower quality; they’re extremely unlikely to become unsafe, says food scientist Dr. Joe Regenstein. 


We also consulted Derek Kasselbaum, co-owner and distiller at North Shore Distillery in   Lake Bluff, Illinois who agreed that open but tightly-closed bottles of liqueurs with dairy don’t require refrigeration, but, he said, “It’s better to refrigerate them after opening.  The flavor will last longer.” He added, even without refrigeration, “they’ll hold up for a year.”  If they’re not closed tightly, the alcohol will start to evaporate, and oxygen will enter the bottle and alter the flavor.


By mistake, I stored a package of frozen veggies in the refrigerator instead of the freezer. How long will it remain safe and tasty to eat?


Here’s a brief answer from Dr. Regenstein: “It will certainly last a few days.  The quality will go down slowly.  From a quality standpoint, the deterioration is likely to be a little faster than fresh product; from a safety point of view, they are probably about the same. If there are any off flavors/off odors either with a raw or cooked product, discard it.”  Off-odors may develop  in the fridge when leaked materials come into contact with dirty surfaces.”


Here is a lengthier response from another food scientist on our Advisory Board, Dr. Tim Bowser: 


“A lot depends on the type of packaging and how long it takes the package to thaw. The contents of paper cartons might thaw and leak in the refrigerator, and that could cause problems for the consumer. Leaky produce packages are more likely to be discarded no matter how edible the contents might be –otherwise, there will be a mess to clean up! Plastic packages will probably hold up very well in the refrigerator (with respect to leakage).  


“In either case (paper or plastic), it might take several days for the contents to thaw, depending on several factors that include the following: the size and shape of the package, physical properties of the particular produce, where it is placed in the refrigerator, and, its initial temperature. Once the food has thawed, it should last about as long as the fresh product would, depending on its condition when frozen and how it was frozen (faster freezing = higher quality).


“Thawed produce will be soft and limp compared to fresh produce, but, if that has no consequence for the intended use, then the thawed produce should be just fine to use as is. Ultimately, the consumers can rely on his/her eyes and nose to help determine when the thawed produce is no longer of high enough quality to eat.”


Does green tea lose its health benefits after a long storage period?


The Tufts University Health and Nutrition Letter asked Selena Ahmed, a Tufts research fellow studying the chemical ecology of tea, to answer this question.   She explains that the chemical compounds in green tea that may have health benefits (“health protective effects in humans”) are called phytochemicals.  The primary phytochemicals responsible for the health claims of green tea are called “catechins.” These are in the highest concentration in fresh tea leaves and decrease over time after harvest.  However processing these leaves (heating, rolling, and drying them) helps to stabilize and even increase the shelf life of catechins.  Nevertheless, catechin levels decline significantly within 6 months.  In other words, if you’re drinking green tea for its possible health benefits, in general, fresh is best.  


To extend the shelf life of tea, store it in sealed packaging in a cool, dark place.


For more information about tea, click here.  


What’s the shelf life of olive oil?


The “Good Eating” section of the Chicago Tribune recently got the answer from Patricia Darragh, executive director of the California Olive Oil Council.  She says that the Council does not endorse the use-by dates printed on some products because they can be arbitrary.  Instead, she says, consumers should check the harvest or mill date, which are on bottles certified by her association but may be difficult to determine for imported oils.  “Two years max” from this date is the length of time she recommends keeping olive oil.


“Olive oil will benefit from storage in a cool, dark place,” Dr. Regenstein advises. “If a cloud develops, it will disappear with heating.”


Denise Gardner adds the following: “Oxidation of  olive oil will start almost immediately after opening it. The oxidation doesn’t really ruin the olive oil, food safety wise, but the taste changes.” 


For more about olive oil, click here


How long can I keep open jars of condiments?


A USA Today article, based upon information from the USDA and food scientists, offers the following advice: Condiments such as catsup, mustard, and vinegar-based dressing are “remarkably safe.”  You can keep them even after a power outage of longer than 4 hours. 


Open jars of pickles and olives should be tossed after being open for 2 weeks, says the USDA.  Dr. Regenstein adds the following: “The important point is that the items be below the liquid line. If the product is in the air, it will spoil more quickly.  Also, black olives are not in a brine (or one that is not as strong as pickle brine), so they’re not going to hold up as long as pickles will.”


How can I keep lettuce from quickly going limp?


USA Today offers this tip: Putting a paper towel in with the lettuce will keep it crisp longer.


To reach more general shelf life advice on this site: click here




Denise Gardner, M.S., Pennsylvania State University, Dept. of Food Science


Timothy J. Bowser, Ph.D., Oklahoma State University, Dept. of Biosystems and Agricultural Engineering


Joe Regenstein, Ph.D., Cornell University, Dept. of Food Science Cocktails  “What is the Shelf Life of Distilled Spirits?” “Tips help you save your food and your dough” “Your Health: When does not wasting food sacrifice safety?”


Chicago Tribune “Good Eating” section  “Watch for harvest dates on olive oils”

August 31, 2011


Tufts University Health and Nutrition Letter  “Ask Tufts Experts: Does tea lose its health benefits if it’s been stored a long time?”  Sept. 2011  “Frank Sinatra Collection”


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