Why Weed's Signature Scent Has Changed Over Time

Summary

Short Wave Podcast Summary

Episode: Why Weed's Signature Scent Has Changed Over Time
Host: Regina Barber
Reporter: Ping Wang
Release Date: June 16, 2025

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Introduction

In this episode of NPR's Short Wave, hosts Regina Barber and Ping Wang delve into the evolving aroma of cannabis. Regina shares her personal experiences with the distinct scents of cannabis during her city walks, setting the stage for an exploration into why and how marijuana's signature smell has changed over time.

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Exploring a Cannabis Grow Farm

Ping Wang takes listeners on an immersive tour of District Cannabis, a hydroponic grow farm located in Hagerstown, Western Maryland. Founded by Andras Kirchner, the facility boasts an impressive annual production of £15,000 worth of cannabis flower.

• Regina Barber [00:16]: "I love long walks. And sometimes on my walks around the city, I get some distinct smells. One of them is cannabis."

• Andras Kirchner [03:41]: "That's our grow facility. That's our weed factory. It's a dream come true."

The tour begins in the nursery, where young cannabis plants are nurtured in controlled environments with high temperatures and humidity. Ping notes that at this stage, the plants emit minimal odors, primarily earthy tones.

• Ping Wang [04:05]: "When I was driving in, I got like a hint of that skunky smell. But in the first growth stages, cannabis doesn't really smell like a whole lot, just earthy, like plants growing."

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The Science Behind Cannabis Scent

The narrative shifts to the indoor flowering rooms, where mature plants release the unmistakable cannabis aroma. Andras showcases their award-winning strains, such as "Gelato Cake," which are characterized by complex terpene profiles.

• Andras Kirchner [05:08]: "So this is definitely one of our more complex profiles. Its Dominant terpenes are caryophyllene, limonene, and linalool."

Terpenes Explained: Terpenes are chemical compounds found in many plants, including cannabis, responsible for their unique smells and flavors. In the case of Gelato Cake, the dominant terpenes contribute to its sweet, grape-like aroma with subtle notes of cognac.

• Ping Wang [05:22]: "These terpenes... they're largely responsible for the different smells and flavors in the plants."

To provide a deeper understanding, Pamela Dalton, a smell scientist from the Menel Chemical Census Center, explains that the classic skunky odor of cannabis is primarily due to sulfur compounds rather than just terpenes.

• Pamela Dalton [06:30]: "They found out that it was actually a sulfur compound, which to my way of thinking, would absolutely be what would be responsible for a sulfur odor."

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Evolution of Cannabis Aromas

The traditional skunky scent was a hallmark of early cannabis strains, favored by breeders in the initial stages of cultivation. However, as recreational use expanded, there has been a significant shift towards developing strains with more diverse and pleasant aromas.

• Pamela Dalton [06:53]: "It's likely that what you're going to smell first are the sulfur compounds."

• Andras Kirchner [07:37]: "A lot of the strains started to really exhibit that skunk smell."

Ping Wang highlights this transition, noting that modern breeding practices aim to incorporate fresher, more appealing terpene profiles, reducing the dominance of the skunky notes.

• Ping Wang [07:23]: "There's been a trend in cannabis cultivation towards new strains and hybrids that are more pleasant to more people."

Jamila Hogan, a cannabis educator and head of Ebony Green, emphasizes the shift towards sweeter and more complex aroma profiles, describing the current dominant strains as having musky, gassy, yet sweet and appealing scents.

• Jamila Hogan [08:31]: "It's the runt picky cake gelato profile... a good sweet funk. She had a good time."

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Market Trends and Consumer Preferences

The evolution of cannabis scents aligns with changing consumer preferences. Modern consumers seek not only the psychoactive benefits of cannabis but also a more enjoyable and varied sensory experience.

• Ping Wang [10:16]: "Nobody buys cannabis just for the smell, right? It's for its psychoactive properties to get high or to relax or to treat a medical condition."

Economic data underscores the booming cannabis market, with Maryland alone seeing over $180 million in cannabis product sales within the first two months of the year.

• Ping Wang [11:10]: "In Maryland,... consumers have spent more than $180 million on cannabis products in the first two months of the year."

At District Cannabis, the production process is highly automated, capable of producing up to four million pre-rolls annually, although current sales are still scaling up to meet demand.

• Andras Kirchner [11:02]: "We have a machine here that is automated and can make 4 million pre rolls in a year."

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Conclusion

The episode concludes with a reflection on how scientific advancements and changing consumer tastes have driven the transformation of cannabis aromas. From the earthy beginnings to the complex, multifaceted scents of today’s strains, the cannabis industry continues to innovate, balancing the functional benefits with an enhanced sensory experience.

• Regina Barber [11:30]: "Thank you for listening to Short Wave from NPR."

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This episode of Short Wave offers a comprehensive look into the intricate world of cannabis cultivation and the science behind its evolving scent profiles, providing listeners with both technical insights and insights into market dynamics.

Transcript

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[Regina Barber]

You're listening to Shortwave from NPR. Hey, Shortwavers. Regina Barber here. And I love long walks. And sometimes on my walks around the city, I get some distinct smells. One of them is cannabis.

[Ping Wang]

I hear you, Gina. It's that skunky, gassy smell that wafts out from doorways and windows and people's stoops. It is that unmistakable smell of weed.

[Regina Barber]

Ping Wang, NPR HEALTH reporter, FRIEND of the SHOW I understand you went on a journey lately to learn about why cannabis smells the way it smells.

[Ping Wang]

Yep, it's true. It went to the depths of Western Maryland. And today I'm gonna take you along with me.

[Regina Barber]

Woo.

[Ping Wang]

We're going to a hydroponic cannabis grow farm where they produce £15,000 of cannabis flower each year.

[Regina Barber]

That is a lot of pot.

[Ping Wang]

That's what he said.

[Andras Kirchner]

It's a lot of weed.

[Regina Barber]

So who's he?

[Ping Wang]

So that's Andras Kirchner. He's the founder and head grower at District Cannabis. They sell in Washington, D.C. and in Maryland. And he's going to be our tour guide today. He's going to take us around the facilities.

[Andras Kirchner]

That's our grow facility. That's our weed factory. It's a dream come true.

[Ping Wang]

So this is a facility that opened in 2020, and they, they do a lot here. They grow baby cannabis plants to maturity. They harvest and dry them. They process and package them for retail sale. And to take the tour, we got suited up jacket.

[Andras Kirchner]

We should get you a lab coat. And then we're gonna have to put your shoes in a little wrap to protect the plants.

[Ping Wang]

And Gina, you and the listeners are gonna come with us.

[Regina Barber]

I'm excited. Let's do it.

[Ping Wang]

We're gonna dive into what's behind that distinctive smell of marijuana and how it's evolved to incorporate more notes of laven citrus and less overwhelming funk.

[Regina Barber]

So today on the show, we'll take you on a smell tour of a cannabis factory and talk about why weed smells the way it smells and how that knowledge is leading to more varieties. You're listening to Short Wave, the science podcast from npr.

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This message comes from Charles Schwab. When it comes to managing your wealth, Schwab gives you more choices like full service, wealth management and advice when you need it. You can also invest on your own and trade on thinkorswim. Visit schwab.com to learn more. This message is from Spectrum Business. From independently owned storefronts just open for business to established professional services run from large offices, Spectrum is committed to delivering connectivity solutions for any size business. Create a plan made for your business with fast, reliable Internet, TV packages, phone mobile services and more. All backed by the Spectrum commitment. From one employee to thousands, Spectrum keeps your business connected. Learn [e-mail] business this message comes from Charles Schwab. When it comes to managing your wealth, Schwab gives you more choices like full service, wealth management and advice when you need it. You can also invest on your own and trade on thinkorswim. Visit schwab.com to learn more.

[Regina Barber]

Okay, so Ping, tell me more about this grow farm you went to in Western Maryland.

[Ping Wang]

So it's out in Hagerstown. It's about an hour and a half northwest of D.C. and it's just off the highway and just down the street from the sheriff's office.

[Regina Barber]

Okay.

[Ping Wang]

And it is a big warehouse and greenhouse compound locked behind barbed wire gates. We started in the nursery where they have racks of these little plants stacked on top of each other.

[Andras Kirchner]

So young plants in the vegetative state. They like high temperatures and humidity. So that's how we keep the environment in here.

[Regina Barber]

And Ping, what did it smell like at this point in the nursery?

[Ping Wang]

Honestly, not a lot. I mean, when I was driving in, I got like a hint of that skunky smell. But in the first growth stages, cannabis doesn't really smell like a whole lot, just earthy, like plants growing. It's only when the plants put that it really starts giving off smells. And that was our next stop, the indoor flowering room.

[Andras Kirchner]

So what you're gonna see in here is our famous gelato cake strain. You are here just about five days before harvest.

[Ping Wang]

It's this warm, humid room with rows and rows of blooming cannabis plants, about 1500 in all.

[Andras Kirchner]

Squeeze it a little bit and then you get the essence in your fingers.

[Ping Wang]

Okay. So to back it up, last year Andrash won the grand champion title in a competition with other weed growers from dc, Maryland and Virginia.

[Regina Barber]

Oh, wow, Congrats to him.

[Ping Wang]

Yeah, it's called the National Cannabis Championship and he won with a strain called Layer Cake. Now, the room that we're in now, it was filled with a cousin to it called Gelato Cake. It's one of their top selling strains. And Kyle Pearl, who's the general manager of operations here, described the smell for us.

[Andras Kirchner]

So this is definitely one of our more complex profiles. Its Dominant terpenes are caryophyllene, limonene, and linalool.

[Regina Barber]

Okay, so wait a second. What are terpenes?

[Ping Wang]

Okay, good question. Yes.

[Regina Barber]

Thank you.

[Ping Wang]

So these are one of several types of chemical compounds that are in cannabis. These terpenes in particular are chemical compounds that are found in a lot of plants, from herbs and citrus to pine trees and in cannabis. They're largely responsible for the different smells and flavors in the plants. Now, what with gelato cake, those terpenes were giving sweetness. And grapes with some cognac on the finish.

[Regina Barber]

Wow.

[Ping Wang]

That was their description. It smelled a little floral, a little hoppy to me.

[Regina Barber]

Okay.

[Ping Wang]

And it had some notes of kerosene as well, or as Andras calls it, gas.

[Andras Kirchner]

It was what a lot of the breeders wanted when they started breeding cannabis. And so a lot of the strains started to really exhibit that skunk smell.

[Ping Wang]

Right.

[Regina Barber]

That skunk smell, like that classic smell of wheat.

[Ping Wang]

Mm. And I spoke with Pamela Dalton, who's a smell scientist at the Menel Chemical Census center, which is this nonprofit research institute. They focus on smell and taste. And she says that that classic weed smell used to be attributed to a skunky terpene. But more recently, research has found a different culprit.

[Regina Barber]

Oh.

[Pamela Dalton]

And they found out that it was actually a sulfur compound, which to my way of thinking, would absolutely be what would be responsible for a sulfur odor. Right. The smell of skunk spray or anything like that.

[Ping Wang]

She says it's that sulfur compound mixed with the fresher smelling terpenes that gives marijuana its signature smells. And in some strains, that skunk note really dominates.

[Pamela Dalton]

We are extremely sensitive to sulfur compounds. So if you have a range of compounds in your cannabis, it's likely that what you're going to smell first are the sulfur compounds.

[Regina Barber]

Wow, that's, like, really fascinating. So, like, even if there's just a little bit of that sulfur, our noses are so sensitive that it's going to, like, be the main thing they smell.

[Ping Wang]

That's right. But Pamela says that there's been a trend in cannabis cultivation towards new strains and hybrids that are more pleasant to more people.

[Pamela Dalton]

I'm almost 70 years old, and the cannabis I smelled when I was 13, 14, 15, smell way skunkier than anything that I experienced now.

[Ping Wang]

And Andrash, our cannabis farmer, has seen this too. He says that in the early days, cannabis breeders and growers were really going for that skunk smell. But in more recent years, as recreational use has grown, cannabis breeders and growers are developing new strains. And there's been a blossoming of varieties with more smells and flavors, from berry.

[Andras Kirchner]

To citrus, lemon, lime, cherry. And a lot of the popular strains are kind of a combination between the gas and another flavor.

[Regina Barber]

I mean, lemon, lime, cherry, citrus, it all sounds a lot like candy.

[Ping Wang]

That's true. And in fact, Jamila Hogan, who goes by J. Mills, she's a longtime weed educator, head of a cannabis experience company called Ebony Green, says that all these varieties have been trending in the same direction.

[Jamila Hogan]

It's the runt picky cake gelato profile. You know it. Cause the buds are oftentimes a little bit purple, super frosty.

[Ping Wang]

Those buds are coated in these tiny glands that produce resin and kind of sparkle in the light. Wow. She calls the whole lineage runtza cake.

[Jamila Hogan]

A lotto the nose on it is musky, gassy, sweet, and skunk. I like to call it the bad girl after brunch smell.

[Regina Barber]

Tell me a little bit more what she means by that.

[Ping Wang]

I had the same question. I was like, say more.

[Jamila Hogan]

She's sweet, but she's funky. She needs to take a shower.

[Regina Barber]

But.

[Jamila Hogan]

It'S a good sweet funk. She had a good time.

[Ping Wang]

J. Mil says that this cakey gelato profile has been dominating for the past five or six years. Before cake, it was cookies. Before cookies, it was gas. But back at the grow farm, we're going from room to room through the production process. Kyle, that general manager, he pointed out a strain called Pave, which is named after super sparkly jewelry. It was flowering in the greenhouse.

[Andras Kirchner]

It's an overwhelmingly kind of cushy, earthy. It's almost a little minty, a little spearminty.

[Ping Wang]

There are stalks of cherry limeade cake that were hanging upside down to dry in the cure room, in the trim room. Andraj says that they are processing a new hybrid called Berry Payton.

[Andras Kirchner]

It is a tropical runts times Gary Payton. Those are the parents. You can definitely smell the fruity profile.

[Regina Barber]

Did you smell it?

[Ping Wang]

I mean, I smelled all these different rooms. Like, literally every room smelled a little bit different. I wish you could smell it. It was like a different combination of musky fruity gas.

[Regina Barber]

Okay, so, Ping. Nobody buys cannabis just for the smell, right?

[Ping Wang]

It's true. Yes. That is a fact. The main reason people buy cannabis is for its psychoactive properties to get high or to relax or to treat a medical condition. And that comes from a whole other class of chemicals like cannabinoids.

[Regina Barber]

Okay.

[Ping Wang]

And marijuana is big business. There's this national survey from 2022 that showed that people in the US are now using cannabis more regularly than alcohol.

[Andras Kirchner]

Wow, this room's gonna be a little loud. Got a lot of machines firing off in this space.

[Ping Wang]

So the weed grown here is headed for the local market and Andrash says that some of it gets packaged and sold as flour or extracted for edibles and dabs and vapes or pre rolled into joints.

[Andras Kirchner]

So we have a machine here that is automated and can make 4 million pre rolls in a year.

[Ping Wang]

Wow.

[Andras Kirchner]

We're currently not selling that many, but we can make them.

[Ping Wang]

And in Maryland, where cannabis has been allowed for recreational use since 2023, consumers have spent more than $180 million on cannabis products in the first two months of the year. So clearly there's a lot of demand for this.

[Regina Barber]

Ping, thank you so much for bringing this reporting. I had a great time.

[Ping Wang]

Thanks so much. Me too.

[Regina Barber]

This episode was produced by Rachel Carlson, it was edited by showrunner Rebecca Ramirez, and fact checked by Ping Wang and Tyler Kwesi Lee was the audio engineer, Beth Donovan is our senior director and Colin Campbell is our senior Vice president of Podcasting strategy. I'm Regina Barber. Thank you for listening to surewave from n.

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