If you've found an unopened bag of chocolate chips lodged in the back of your pantry, check the sell-by date to determine if they're still usable. Bulk bags may not carry a freshness date, though, so you'll have to rely on your memory of purchase and other indicators to determine if the sweet bits have passed their prime.
Stashing your chips in a cool, dark pantry gives you two to four months in which to use them. Place them in the refrigerator and they'll last six to eight months. The freezer preserves them the longest -- for up to three years, according to the website EatByDate. If you do take chips out of the refrigerator or freezer and let them come to room temperature, condensation may form and alter their appearance. They'll still be safe to use in baking and you'll detect no change in their flavor or texture. Milk chocolate spoils sooner than high-quality dark chocolate, which can last up to 10 years according to "Real Simple" magazine.
The ability of chocolate chips to last many months in the refrigerator or years in the freezer, depends on proper storage. Keep them away from heat and in a sealed container. If you live in a warm climate, your best bet for storage is the fridge. Place chocolate chips in air-tight wrapping -- this will help ensure they don't absorb flavors from other refrigerated foods.
Signs of Spoilage
Signs that your chocolate is not at its best include a bloom of white and a grainy texture. Neither of these make the chocolate harmful to you, but definitely diminish chip appeal. A highly bitter flavor or garlicky aftertaste are clear indicators of a spoiled batch.