What’s the Shelf Life of Halloween Candy?

The spookiest time of year is upon us, and with it comes piles of chocolates, chews, caramels, nougats, crunches, bars, and patties. Estimates from the National Retail Federation suggest Americans will spend close to $2.6 billion on candy this Halloween: While many purchase candy in anticipation of trick-or-treaters, others take advantage of day-after-Halloween sales to stock their own pantries. Chocolate confections like Reese’s Peanut Butter Cups and Twix will make up a large portion of sweets purchased, according to a FiveThirtyEight survey of the country’s favorite fun-sized candies. While chocolate candies may top the chart of Halloween favorites, fruity varieties like Starburst, Skittles, and gummies aren’t far behind (along with the controversial candy corn, of course).

Certain types of confections contain preservatives designed to prevent spoilage. Butylated hydroxyanisole and the antioxidant TBHQ, which are both found in chocolate candies including Reese’s peanut butter cups, work to prevent fats and oils from becoming rancid, while citric acid in candies like Skittles and lemon drops serves a dual purpose of providing tartness and maintaining freshness.

But it doesn’t mean those candies last infinitely, and in the unlikely event that seasonal candy lingers in the house beyond November, it’s important to know when said sweets are past their prime. Here’s a handy guide to just how far past Halloween you can enjoy the fruits of all that trick-or-treating labor.

What causes candy to spoil?

A candy’s shelf life is directly influenced by its ingredients. “For most sugar-based confections, losing moisture or drying out is the main reason,” says Richard W. Hartel, a professor of food engineering at the University of Wisconsin. “Find an old box of Peeps or Dots or jelly beans, and you’ll quickly see what that means.” Packaging can help sugar-based candies retain their shelf life: Such candies are often wrapped in plastic to prevent moisture loss, but once you open the package and expose the candies to air, they can dry out within days or weeks.

There are several ways chocolate can spoil. “One is fat bloom formation, where the cocoa butter recrystallizes as white spots on the surface,” Hartel says. Especially in the case of milk chocolate, this can make the candy taste rancid — though all the sugars and preservatives probably mean it won’t make you sick.

Over time, even if protected from light and warmth, chocolate might absorb moisture and consequently won’t have the same viscosity when melted, and might feel gritty on the tongue.

There are several factors that can instigate candy spoilage, including moisture, light, heat, and a candy’s fat content, according to food scientists from Kansas State University. Overall, general recommendations suggest the pantry is the best place to store sweets, away from light and moisture. Certain candies (like chocolate) may be okay in the fridge or freezer, but any that contain fruit or nuts should not be frozen.

How long does chocolate last?

The shelf life of chocolate varies based on type. Dark chocolate will last one to two years in foil if kept in cool, dark, and dry places, while milk and white chocolate will last up to 10 months. The higher milk fat content in white and milk chocolates shorten its shelf life when compared with dark chocolate.

Alexandra Whisnant, a Ladurée and Chez Panisse alum who runs a small-batch chocolate business in Boston, recommends storing chocolate in places away from sunlight and humidity; “just below room temperature is best,” she says. But avoid putting it in the fridge, which Whisnant says “will lead to condensation on the surface of the chocolate.”

But, Whisnant says, it’s probably best to just eat artisanal, small-batch chocolate — which usually contains no preservatives except for the sugar that’s in it — as soon as possible. “My chocolates are best eaten within 7 days after they are made. This allows for the brightest flavor and most luscious texture.”

Beyond specialty filled and flavored chocolates, Whisnant signs onto the two-year time frame for dark chocolate bars and approximately a year for white chocolate. “Of course, with actual Halloween candy, the thing to do is put it all in the freezer,” she says.

What’s the shelf life of hard candy?

Hard candies essentially have an indefinite shelf life, provided they are stored properly. Items like lollipops, Jolly Ranchers, and other individually wrapped candies do best without exposure to moisture. If such candies do spoil, they’ll appear sticky or grainy as a result of temperature changes or sugar crystallization, and may experience changes in flavor.

How long does marshmallow last?

Marshmallows are a sugar-based confection with a shelf life of roughly six to eight months. By nature, they contain more moisture than many other candies, so depending on how they’re stored, they’ll either lose moisture or become more sticky. They are best stored in dry, cool places or at room temperature.

What about caramel, nougat, and candy corn?

Caramel and nougats last six months to a year at room temperature and away from heat and light, while candy corn can make it as far as nine months if kept sealed. (So that open bag you used to top your Halloween cupcakes should probably get tossed around January.)

What about candy expiration dates — shouldn’t I just adhere to those?

Most candies do have expiration dates, but like most foods, these dates serve more as guidelines for when to consume them. It’s generally fine to eat candy past its expiration date, though the quality and texture does decline after a certain point.

What happens if I eat expired candy?

It’s unlikely that eating a sugar-based confection, like hard candy or candy corn, past its prime will affect your health. Hartel says it’s simply an issue of quality decline, not health; that is, “unless a tooth breaks.” Same goes for chocolate: Though it may exhibit some signs of age on the surface in the form of a chalky white “bloom,” eating it doesn’t actually present any health risks, though the texture or flavor may be off.

When should I throw out my Halloween candy?

A good rule of thumb is to simply toss it when it stops tasting good. You probably won’t get sick — unless you eat all of it in one sitting, that is.

Dana Hatic is an associate editor for Eater Boston.