Why Weed's Signature Scent Has Changed Over Time

The skunky smell of cannabis may be going out of style. NPR's science correspondent Pien Huang https://www.npr.org/people/729920828/pien-huang visited the grow facility for District Cannabis, which sells weed in Washington D. C. and Maryland. On her tour, she learned why cannabis smells the way it does. Plus, how many strains have been bred — to smells like lavender, citrus and even cookies. Read more of science correspondent Pien Huang's reporting on this topic https://www.npr.org/2025/03/25/nx-s1-5243317/weed-cannabis-skunk-smell-aroma here https://www.npr.org/2025/03/25/nx-s1-5243317/weed-cannabis-skunk-smell-aroma, or check out the entire special series, "How safe is your weed? https://www.npr.org/series/g-s1-41928/weed-cannabis-safety-regulation" Questions about the science behind the mysteries, events and... smells... all around us? Email us at [email protected] mailto:[email protected] – we'd love to hear your ideas! Listen to Short Wave on Spotify https://n.pr/3HOQKeK and Apple Podcasts https://n.pr/3WA9vqh. See pcm.adswizz.com https://pcm.adswizz.com for information about our collection and use of personal data for sponsorship and to manage your podcast sponsorship preferences. NPR Privacy Policy https://www.npr.org/about-npr/179878450/privacy-policy

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• 0:00Speaker 00

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• 0:18Regina Barber?

  You're listening to Short Wave from NPR.

• 0:23Regina Barber?

  Hey, Short Wavers, 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.

• 0:33Speaker 02

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

• 0:42Regina Barber?

  Ping Wong, 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.

• 0:48Speaker 02

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

• 0:54Regina Barber?

  Ooh.

• 0:55Speaker 02

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

• 1:02Regina Barber?

  That is a lot of pot.

• 1:04Speaker 02

  That's what he said.

• 1:05Speaker 03

  It's a lot of weed.

• 1:06Regina Barber?

  So who's he?

• 1:08Speaker 02

  So that's Andras Krishner. 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.

• 1:19Speaker 03

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

• 1:26Speaker 02

  So this is a facility that opened in 2020, and 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.

• 1:39Speaker 03

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

• 1:49Speaker 02

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

• 1:51Regina Barber?

  I'm excited. Let's do it.

• 1:54Speaker 02

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

• 2:03Regina 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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• 3:50Regina Barber?

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

• 3:55Speaker 02

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

• 4:03Regina Barber?

  Okay.

• 4:04Speaker 02

  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.

• 4:15Speaker 03

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

• 4:25Regina Barber?

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

• 4:28Speaker 02

  Honestly, not a lot.

• 4:30Regina Barber?

  Okay.

• 4:30Speaker 02

  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.

• 4:37Regina Barber?

  Okay.

• 4:38Speaker 02

  Just earthy, like plants growing. It's only when the plants bloom that it really starts giving off smells. And that was our next stop, the indoor flowering room.

• 4:47Speaker 03

  So what you're going to see in here is our famous Gelato Cake strain. You are here just about five days before harvest.

• 4:55Speaker 02

  It's this warm, humid room with rows and rows of blooming cannabis plants, about 1,500 in all.

• 5:02Speaker 03

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

• 5:06Speaker 02

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

• 5:14Regina Barber?

  Oh, wow. Congrats to him.

• 5:16Speaker 02

  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.

• 5:32Speaker 05

  So this is definitely one of our more complex profiles. Its dominant terpenes are cariofylline, limonene, and linolol.

• 5:41Regina Barber?

  Okay, so wait a second. What are terpenes?

• 5:44Speaker 02

  Okay, good question.

• 5:45Regina Barber?

  Yes, thank you.

• 5:46Speaker 02

  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, with Gelato Cake, those terpenes were giving sweetness and grapes with some cognac on the finish.

• 6:11Regina Barber?

  Wow.

• 6:11Speaker 02

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

• 6:14Regina Barber?

  Okay.

• 6:15Speaker 02

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

• 6:21Speaker 03

  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.

• 6:32Regina Barber?

  Right, that skunk smell, like that classic smell of wheat.

• 6:35Speaker 02

  Mm-hmm. 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.

• 6:53Regina Barber?

  Oh.

• 6:54Speaker 06

  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.

• 7:07Speaker 02

  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 odor really dominates.

• 7:16Regina Barber?

  Hmm.

• 7:17Speaker 06

  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.

• 7:30Regina 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 gonna like be the main thing they smell.

• 7:39Speaker 02

  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.

• 7:47Speaker 06

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

• 8:01Speaker 02

  And Andrasch, 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.

• 8:20Speaker 03

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

• 8:35Regina Barber?

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

• 8:40Speaker 02

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

• 8:55Speaker 07

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

• 9:04Speaker 02

  Those buds are coated in these tiny glands that produce resin and kind of sparkle in the light. She calls the whole lineage runts a cakealato.

• 9:14Speaker 07

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

• 9:24Regina Barber?

  Tell me a little bit more what she means by that. I had the same question. I was like, say more.

• 9:28Speaker 07

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

• 9:36Speaker 07

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

• 9:38Speaker 02

  Jay Mills 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.

• 10:01Speaker 05

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

• 10:09Speaker 02

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

• 10:19Speaker 03

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

• 10:28Regina Barber?

  Did you smell it?

• 10:30Speaker 02

  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.

• 10:39Regina Barber?

  OK, so Ping, nobody buys cannabis just for the smell, right?

• 10:43Speaker 02

  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.

• 10:57Regina Barber?

  OK.

• 10:57Speaker 02

  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.

• 11:06Regina Barber?

  Wow.

• 11:07Speaker 05

  This room's gonna be a little loud. We've got a lot of machines firing off in this space.

• 11:13Speaker 02

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

• 11:25Speaker 03

  So we have a machine here that is automated and can make 4 million pre-rolls in a year. We're currently not selling that many, but we can make them.

• 11:39Speaker 02

  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.

• 11:53Regina Barber?

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

• 11:56Speaker 02

  Thanks so much. Me, too.

• 12:00Regina Barber?

  This episode was produced by Rachel Carlson. It was edited by showrunner Rebecca Ramirez and fact-checked by Ping Wong and Tyler Jones. Kwasi 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 Shorewave from NPR.