There's A Reason Hershey's Famous Chocolate Kisses Are Packaged In That Iconic Foil

One of the most iconic candies in the world, Hershey's Kisses were invented in 1907. They have been in production nearly ever since, with the exception of World War II. For five years, aluminum was being rationed for the war effort, and Hershey focused on making chocolate for the military during that time. Aside from that, Kisses have always been wrapped in thin foil to keep them fresh. In addition to the iconic visual appeal, foil preserves the taste of the chocolate for two years or more in ways that other packaging materials can't.

The foil is an extremely effective barrier against air, moisture, light, other contaminants that can affect smell and flavor. Additionally, foil can be molded exactly to the shape of the chocolate, unlike plastic or paper wrappers.

Kisses, small as they are, benefit from lightweight packaging. Foil is very lightweight, making transportation more efficient. This is important since aluminum is generally more expensive than plastic or paper packaging. Its thin design helps save space and reduces shipping and storage costs, which offsets its higher material cost. To that end, the foil Hershey uses is 0.00035 inches thick, according to Hershey's (via Design Life-Cycle), making it about half the thickness of normal kitchen foil.

The idea of wrapping something to keep it fresh is a general one. Specific aspects of food, and chocolate in particular, need to be preserved to maintain quality. Oxygen, moisture, and ultraviolet light can significantly degrade chocolate if it is not protected from them.

Research in the International Research Journal of Biochemistry and Bioinformatics confirms that oxygen causes the fatty acids in chocolate to oxidize. This results in the creation of new compounds that both smell and taste bad, even spoiled. UV light can exacerbate this issue, and moisture levels can cause chocolate to develop a white coating, a process known as blooming. Bloom can be reversed, and it's harmless, but it makes chocolate look unappetizing. You wouldn't want to open a new piece of chocolate and see it.

Foil is one of the best barriers against all of the things that can make chocolate spoil or degrade. While Hershey switched to a fin-seal film wrapper for its chocolate bars, Kisses have kept the iconic foil. Modern plastic wrappers may now be more advanced, but the foil wrapper on a Kiss is well-recognized and still effective at doing its job for Kisses and their many flavors.