Raisins are a staple food throughout North America and elsewhere in the world. Simple, wholesome, sweet, and as useful in recipes as they are as a standalone snack.
Raisins have a lot going for them. Raisins also make for pretty good survival food, both as carried rations and as long shelf life fare at home.
But raisins won’t last forever. Or will they? Do raisins go bad? And how long do they last?
Yes, raisins will eventually go bad, but with proper storage, they can last for quite a long time. Unopened packages of raisins generally last for 2-3 months past the “best by” date if stored in the pantry at room temp, or about two months once opened.
As one might expect, higher temperatures and humidity accelerate spoilage of raisins.
Drying fruit is a great way to extend its safe shelf life and raisins are no exception. But even though they last for a long, long time and remain delicious they will not last indefinitely.
That being said, there are ways to improve their shelf life no matter how you are storing them. Keep reading to learn more.
What are Raisins?
Raisins are grapes that have been dried in the sun, in an oven or using a dehydrator appliance.
The water is removed from the grape, leaving behind a chewy, wrinkled fruit that is high in sugar and antioxidants. All raisins start out as grapes, but not all grapes become raisins.
Grapes destined to be raisins are usually of the Thompson Seedless variety, although there are many other varieties of grapes that can be used.
The most common type of raisins are the brown ones, but there are also black, green, and red varieties.
All raisins taste sweet because of the high sugar content. The sugar, in the absence of moisture, also acts as a preservative, which is one of the reasons why raisins last so long. It is also why they are so tasty!
With the water weight of the grape gone, the sugar taste is maximized, making raisins a higher calorie food by weight compared to whole grape.
This has made raisins a fixture food for snacking and as an ingredient in all sorts of dishes.
From trail mix to cake and even chicken salad, raisins add a touch of sweetness and interest to whatever they are added to.
What is the Typical Shelf Life of Raisins?
Raisins will usually last for 2-3 months past their listed “best by” date if sealed and stored properly.
Once opened, they should be consumed within two months for best quality but may last longer with no ill effects.
Raisins stored in the fridge or freezer can last for six months to a year beyond normal room-temperature storage.
What Conditions Affect that Shelf Life?
The big factors that affect the longevity of raisins are the type of storage container, the temperature of the storage environment, and the humidity level.
For long-term storage of raisins, it is best to use an airtight container. Glass jars with screw-on lids work well, as do resealable bags and canning jars.
The key is to keep the air out and the raisins in a consistent environment. That way they don’t draw in moisture or get exposed to mold spores that may be in the air.
Those wimpy cardboard containers they come in are no good once they are opened; if you aren’t going to eat the raisins soon thereafter transfer them into a better container.
Temperature is, as always, a big concern for food storage. Raisins will last the longest when stored at cool temperatures, ideally below 68 degrees Fahrenheit (that’s 20 degrees Celsius for you non-Freedom Unit people).
If you are going to store them for longer than a couple months, the freezer is your best bet.
But even if you are just storing them in the pantry, try to find a spot that is not in direct sunlight and not near any heat sources.
And last but not least, moisture control. Humidity. Raisins are a dried food, so they need to be kept in a relatively dry environment to prevent them from rehydrating and promptly going bad.
A humidity level below 50% is ideal, but 60% should be fine as long as the raisins are stored in an airtight container.
How to Tell if Raisins Have Gone Bad
Even fruit that lasts as long as a raisin will, eventually, spoil. If you don’t want to risk a case of food poisoning you’ll need to know how to spot the signs.
To the naked eye, bad raisins may not look all that different from good ones. But there are a few things you can look out for to tell if raisins have gone bad:
- The color may have changed or faded. This is especially true for red and black raisins which may bleed their color or appear mottled.
- The texture may have changed. If the raisins are old they may be harder, or if they have been exposed to moisture they may be plump or gummy.
- Mold growth. This is a sure sign that the raisins have gone bad and should be discarded immediately.
- Tangy smell. If the raisins smell sour or off they have gone bad and should not be eaten. This is due to the fermentation process that has begun to occur.
If you see any of these signs, it is best to discard the raisins. While they may not look or smell that bad, raisins that have spoiled may make you sick.
One Tip to Maximize Shelf Life of Raisins
There is one kitchen gadget that can pay dividends when it comes to extending the reliable shelf life of your food, even something like raisins: the vacuum sealer.
A vacuum sealer will remove all the air from a storage container and create a tight seal. This not only prevents new contaminants from getting in, but it also slows down the aging process.
If you are going to store raisins for more than a couple months, or if you want to make sure they have the best possible chance to last in a humid environment, sealing them in a special mylar bag with a vacuum sealer is your best bet.
Tom has built and remodeled homes, generated his own electricity, grown his own food and more, all in quest of remaining as independent of society as possible. Now he shares his experiences and hard-earned lessons with readers around the country.