The Audit Podcast: How a few seeds – and a little luck– gave us the iconic Pueblo chile

pueblo chile
Using seeds from his uncle, Michael Bartolo,a senior research scientist emeritus at CSU’s Arkansas Valley Research Center, bred the now-iconic Pueblo chile. Photo by Bill Cotton/CSU

Welcome to Colorado State University’s new podcast, The Audit, featuring conversations with CSU faculty on everything from research to current events. Just as auditing a class provides a fun way to explore a new subject or field, The Audit allows listeners to explore the latest works from the experts at CSU.

The iconic Pueblo chile is having kind of a moment right now. Beloved for its meaty texture and, of course, its fiery heat, you can find the pepper in everything from salsas and hot sauce to beer and fudge. But if it hadn’t been for an inherited seed stock – and a little luck – Pueblo’s most famous chile variety might have been lost forever.

Audit host Stacy Nick spoke with Michael Bartolo, a senior research scientist emeritus at CSU’s Arkansas Valley Research Center – and the innovator behind one of Pueblo’s “hottest” crops.

This transcription has been lightly edited for clarity.

I want to start with the story of how you got into the Pueblo chile business. It sounds like we have you and your uncle to thank for what we now know as the Pueblo chile.

The production of chiles was a long progression of multi generations, contributing to the development of the Pueblo chile and that certainly was the case in the Pueblo area. The Pueblo chile came into the area in the early 1900s as a landrace form that we historically called the “mirasol.” Mirasol, meaning looking at the sun, type of chile. So, that was the kind of the historical landrace of chile that had been grown there for many years. Many of the families that farmed in that area – many of them immigrated from Italy – produced that chile, including my family. And so, they produced that year after year after year and began selecting and saving their own seeds. Over generations they actually developed their own landrace of the Pueblo mirasol chile. 

Now, really, what started this other kind of side shoot is that I was away at college in 1980 and that’s when my uncle, Harry Mosco, passed away. I was still going to graduate school at the University of Minnesota. When I graduated, I started in my new position right here with Colorado State University in 1991. I ended up working at the Arkansas Valley Research Center here in Rocky Ford, which is only about 45, 50 miles away from where I grew up. When I came here, my dad gave me a bag of seed that my uncle had grown, it was stored in his garage. And he said, “Well, here’s this extra seed. You’re the horticulturalist, here you can have it.” 

I had no plans, no aspirations, to be a pepper breeder. But I had some extra room in a test plot the following year, and I began growing it out. So, I grew out four rows of that chile, and it looked pretty typical to what it usually was. But in that population, I was able to find one particular plant that kind of caught my attention, and I began saving that seed from that first selection. After, I think it took me seven or eight years of doing what we call single-plant selections from that original plant, I got something that was pretty stable, pretty unique. From there I began bulking up the seed. We released it and gave it out to growers, and it kind of took off from there. So, a lot of fortunate things are coming into play. I’m not sure how much skill it is, but it’s a lot of fortunate things that happen to be all in the same area and the inherited seed and all that came together to really produce what we now know as the one of the main varieties of Pueblo chile, which is now called Mosco, named after my uncle.

pueblo chile
What do you think it is that makes the Pueblo chile so special?

There’s a lot of things. It’s got great flavor. It’s got a very thick wall to it, meaning it’s typically used, from a culinary perspective, roasted. When it’s roasted, you want that to have a real thick wall, a real meaty texture to it because it holds up to that roasting process. It’s pretty pungent, meaning it’s got a pretty high heat content, and people that like to consume a lot of chile seem to prefer that. So, those two things from a horticultural standpoint make it important. 

But I think there’s other things that are harder to put your finger on what makes it so important. I think part of it is that chile in general, and in particular this Pueblo chile throughout the generations – even before we developed this Mosco variety – was really woven into the tapestry of the cultures here in Southern Colorado and particularly in the Pueblo area. There are so many ethnic cultures that incorporate the chile into the foods they eat and in so many of the traditions that we share and value here in this part of the state. It’s also got some of these other characteristics that are really hard to describe, but for the most part they become part of our culture rather than just a thing that provides calories. It’s really part of our identity, and I think that’s what makes it so special.

You mentioned the heat element earlier. How hot is the Pueblo chile on the Scoville scale? Hotter than that other chile down the road that we won’t mention by name?

It’s okay to mention Hatch chile. They grow a very fine chile down there. Everybody asks me to try to compare them. Chiles really encompass a wide range, but generally the Pueblo chile has about 5,000 Scoville units. Just for reference, a bell pepper has zero. Your typical New Mexico Hatch Anaheim type chile has about 1,500, maybe 2000 Scoville units. So, it’s considerably hotter but less hot than, say, a jalapeno or some of these cayenne-type peppers.

And the Mosco is a publicly released variety, is that correct?

Correct. So, that was released to the public in the early part of 2000, around 2002. We just generally released it as an open pollinated variety and decided at that time just to get it out to the public. I believe in that kind of thing from Colorado State University’s perspective. This variety is really not widely grown like some of the other crops that we produce; it’s a pretty niche crop. So, I think really to live out that land-grant mission, we felt it was best to get that out to the public and really help increase some of the economic impact on the local economy.

Now, you’re still working on the chile, right? The Moscoe of today is not exactly the Mosco of 10, 20 years ago.

To me, it’s this long progression. It’ll never be finished. There are always new things that I’m looking for in characteristics and traits in chile peppers. Technically, I retired in December of 2021, but I have an agreement with Colorado State University that I’m going to continue to work on the chile peppers, and I continue to do that and we’re always looking for better improvements. There’s always some horticultural trait or some characteristic that we look for. Some of the things I’m looking for are that wall thickness, a bigger fruit size, earlier maturity and flavor. We want to make sure we retain that characteristic flavor. That’s part of our heritage is to have that full-body flavor. And then we’re also looking for a wider range of pungency, so it’ll satisfy everybody. I’ve got lines that are relatively mild – almost no heat at all – to ones that are maybe two or three times hotter than that original Pueblo chile. Believe it or not, those hotter lines, people that consume big quantities of chile really like it hot.

I have heard that you actually don’t like spicy things. Is that true?

That is true. I don’t eat very much spicy food. People always ask me, what’s my favorite salsa or the way to eat it. My expertise, as far as the culinary aspects of it, falls off a very steep cliff right after the pepper has been picked off the plant. What I look for is somewhat hard to describe because I’m looking at so many factors when I’m selecting some of these. I’m looking for how the plant stands up, the architecture of the plant, and when I feel the pod, I want to make sure it has a density to it. There are things I wish I could describe to you in detail, but when I’m out there, I know what I like, and I know what to select for. I’ll go through hundreds and hundreds of plants in a particular year looking for that, because I feel like there’s always a hidden gem out there. And if I find a plant that has a unique characteristic, I’ll save the seed from that and see if it’ll come true to form next year. But the basics are things like good plan architecture, nice pod size and good yield, but ultimately, it’s got to come down to flavor.

So then how do you test the flavor? Do you have some taste testers that you employ and if so, how do I get on that list to be one?

I do a little tasting myself, so I kind of avoid the heat of it because I just bite the very tip of it. A lot of the capsaicin, or that chemical causing compound that causes the heat sensation, is located more toward the top end of the pepper. So, if you just bite the tip, you don’t get much. But I’ve thought about this immensely, about how to get a good taste testing and typically you’d employ a taste panel usually of college students. Not that I think they’re bad, but I don’t think they would necessarily have the experience. So, I’ve got some good friends here – a couple of ladies that I work with and have known for years, one of them is 86 years old. She’s a wonderful, beautiful lady. She’s been cooking and preparing chile all of her life. She grew up raising chile and picking it. I usually give her those chiles and see what she thinks. She knows what it takes to prepare a wonderful meal because she’s, you know, thousands of meals for her family over these decades. So, I rely on people like that that have not only an understanding of the physical attributes of the chile, but some of those intangible things that we talked about: How does it prepare, and how does it add flavor to a particular dish?

It seems like the Pueblo chile has really brought a lot of attention to the area. There’s the festival, the fun feud with that other chile down the road. It’s become a really popular vegetable. Is it a vegetable? Is it a fruit? It has seeds.

The pod itself is technically, from a botanical perspective, a fruit, but we call it a vegetable because that’s the way it’s used in culinary aspects, as a vegetable. But it certainly has increased in popularity a lot. A lot of that can be attributed to some of the work that the Pueblo Chamber of Commerce has done. There was a man who was a director of the Pueblo Chamber of Commerce named Rod Slyhoff, who was a big cheerleader for that. I remember getting together with him now almost 30 years ago and we sat down and worked on ways to promote the Pueblo chile. That’s when we had that brainstorming session to come up with the Chile & Frijoles Festival in those early years. It was a very, very modest gathering, but he really ran with that over the many decades, and he really should be championed as the father of that festival. And that festival has drawn a lot of attention and people to Pueblo and really amplified it beyond that borders of Pueblo County up and down the Front Range. From that, it’s been a catalyst for a lot of other entrepreneurial ventures and adding it to many other types of food.

It seems like culturally it’s become such a staple. It’s really become this identifier for the area almost.

That’s true, it’s woven into so many of our good memories, even mine. Now, my background is of Italian descent. Typically, you don’t associate hot chile peppers with that culture. But that’s what’s so unique about the Pueblo area is that it is really a community consisting of immigrants from all over the world. And so chile was the one thing that was woven, the thread that bound all those different cultures together. You can imagine all these different cultures that are coming to work in the area, whether it be for mining or farming – a big employer at that time was the steel mill – and so that drew a lot of people from all over the world. But chile was kind of the common denominator, and it really became part of the binder to that community. I remember even as a child myself, how that was incorporated into our food and how it was so important to our family gatherings. It was always there.

Does having this kind of a trendy crop help Colorado agriculture in general? Does it maybe get more people to think about where their food comes from?

That’s exactly right, and I think it’s important. We obviously have a lot of attention looking at things like the Palisade peaches, the Olathe sweet corn, the Rocky Ford melons, the Pueblo chile; those are all iconic crops. But they help raise the ship for a lot of our other agricultural products. Colorado is really a livestock-producing state, and a lot of the things that are very important maybe don’t get all the attention that they deserve. Potatoes, wheat, all those things are very important crops. Some of these other crops get a lot of fanfare, but hopefully they help lift the boat for the entire agricultural industry.

So, my last question is, as the preeminent expert on Pueblo chiles, what’s the best way to serve them? What is your favorite dish?

I’ve gotten that question a lot. As I mentioned, my culinary expertise is very small. But to me, the best way is the way I grew up eating them. I remember my grandmother would make fresh Italian bread and just having a roasted chile with a fresh piece of Italian bread was heaven. That’s what I think is really good about Pueblo chile, is to have it in its purest form. For me, it’s with a fresh piece of Italian bread or a freshly made tortilla and just the chile itself, roasted, so you get that nice, charred flavor on the background and there’s sweetness and there’s spiciness all mixed in there. To me, that’s the true essence of eating a Pueblo chile.

About The Audit

Colorado State University’s new podcast, The Audit, features conversations with CSU faculty on everything from research to current events. Just as auditing a class provides a fun way to explore a new subject or field, The Audit allows listeners to explore the latest works from the experts at CSU.