Why is pumpkin spice so popular? Scent scientists explain the hype

The morning air is crisp, while amber-colored leaves crunch underfoot, leaving a small orchestra in your wake. Pumpkins line porches and safe inside under a blanket their residents are already bookmarking new Thanksgiving recipes.

This collection of moments can only mean one thing: it’s pumpkin spice latte (PSL) season.

Fragrant with notes of cinnamon, clove, and nutmeg this fall classic is a sweet and cozy reminder of the season. Originating at Starbucks in 2003, you can now find variations of pumpkin spice latte at local and chain coffee shops across the country and injected into grocery items.

But the reason this drink has a cult following may have just as much to do with its actual taste as with the nostalgia we’ve cultivated around it, Sarah Cormiea tells Inverse.

Cormiea recently defended her doctoral thesis at Johns Hopkins on the science of scent perception and is part of the university’s Dynamic Perception Lab. This lab is helmed by Jason Fischer, a professor of psychology and brain science at Johns Hopkins, and in part studies how olfaction — or smelling — affects how we perceive and construct our own realities.

When it comes to memory, scent is one of the most powerful triggers. It’s especially powerful when it’s confined to a period of time.

“We know that when you go back to your grandma's house or something and you're like ‘ah smells like grandma's house’ that can remind you of all my childhood summers there,” Cormiea explains. “But if you visit grandma every day you don't get that intense memory experience.”

How does smell affect memory?

We use our senses to help us more deeply encode our memories, Fischer tells Inverse.

For example, you might notice the softness of a loved one’s sweater or the smile lines of your friend’s face. These kinds of sensations are processed in your brain’s central hub called the thalamus, Cormiea explains.

Smells, on the other hand, take an express route through our brains straight to the piriform cortex. This is an important difference, Cormiea says, because this area of our brains is specifically tied to the creation of memories.

Olfaction is “bundled up with these brain regions that do memory and emotion,” Cormiea says. “That's one of the reasons it might be the case that [olfaction] is such an evocative sense.”

As a result, smelling a familiar scent can be a strong trigger for a memory — especially if it's a scent from childhood. This connection can weaken if we’re over-exposed to a smell but works particularly well for scents — like a pumpkin spice latte — that are familiar but seasonal or limited.

What is pumpkin spice?

Despite its name, pumpkin spice does not contain fine grains of dehydrated pumpkin.

“You're getting this very this consistent dose of those aromas everywhere you go.”

Instead, it's typically more of an all-purpose autumnal spice that contains spices like cinnamon, ginger, cloves, and nutmeg. However, according to the ingredients listed on the Starbucks website, your PSL may actually contain some traces of the real deal.

The pumpkin spice sauce included in the Starbucks beverage includes, in addition to other natural flavors:

• Sugar
• Condensed Skim Milk
• Pumpkin Puree

In addition to flavoring coffee drinks, you can also find pumpkin spice flavoring everything from breakfast cereal to cheese and in the scent of products ranging from candles to kitty litter. Trader Joe's, meanwhile, has gone all-in on pumpkin products.

Why is pumpkin spice so popular?

It’s precisely the sheer breadth of pumpkin spice’s reach that makes it such a powerful memory for us, explains Fischer.

“This time of year you go out to the store and there's pumpkin spice candles and probably even pumpkin spice laundry detergent,” says Fischer. “You're getting this very this consistent dose of those aromas everywhere you go. Pumpkin spice has a particular set of things going for it that cement itself in our minds.”

The context in which we experience pumpkin spice flavors also influences this connection.

While fall may be experienced differently around the world or for individuals, the overwhelming marketed experience of fall in the U.S. is one that is cozy, warm, and safe. This means that grabbing a pumpkin spice latte on your way to an apple orchard or pumpkin patch is only recementing this association every year.

While Cormiea and Fischer say they haven’t tested the influence of pumpkin spice in their lab directly — though they have tested its constituent ingredients, like cinnamon and vanilla — they say its popularity is no surprise given all these factors.

Through the lab’s other olfaction research, they’ve learned that simply knowing your drink is flavored with pumpkin spice may also strongly contribute to its appeal. In other words, if you were to try the drink without the PSL fanfare, it might not hit the same.

“When you have the label, and you have the smell,” Cormiea says. “You are reevaluating how you interpret the smell that's coming in right — you're judging those sensory dimensions a little bit differently and you're constructing your experience a little bit differently.”

This is something you can try out for yourself at home too, Fischer says, who will occasionally blind-sniff spices in his cabinet just to see if he can still correctly recognize them.

It’s these strange illusions of olfaction that the pair say make it such an interesting and underappreciated part of our daily lives.

“Nobody really notices how much you know their sense of smell is contributing to their life,” Cormiea says. “For example, you go into your house and it smells like your house and it makes you feel safe and warm. I just think people should think about that and appreciate their sense of smell a little bit more.”

CHECK, PLEASE is an Inverse series that uses biology, chemistry, and physics to debunk the biggest food myths and assumptions.

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