Short answer: nearly every New Mexican chile variety NMSU has released since 1913 falls between 0 and 9,500 Scoville heat units, and mild, medium and hot are seller's words rather than measurements. Nobody grades chile for heat the way they grade it for size and shape, so the label tells you what one seller decided, and the same variety can land in a different place from one season to the next.
Once you know the labels are relative you can stop looking for a number and start asking the question that actually gets you the right jar: relative to what?
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Why nobody measures it
The federal grade standards for peppers other than sweet peppers sort them into U.S. Fancy, U.S. No. 1 and U.S. No. 2 based on maturity, firmness, shape, size, color and freedom from damage. Heat isn't in there. USDA's Agricultural Marketing Service will tell you whether a pod is misshapen, and it has nothing to say about whether it'll hurt.
New Mexico does regulate chile labels, but not for heat either. The New Mexico Chile Advertising Act exists to stop somebody selling you Peruvian chile in New Mexico packaging, and the New Mexico Department of Agriculture describes its job as ensuring "the sale of authentic New Mexico 'chile pepper' products." It governs where the chile came from. What happens when you eat it is between you and the seller.
So when you see mild, medium, hot and XXHot on a label, you're reading a seller's own scale, calibrated to that seller's own crop and customers. Ours is calibrated to the Hatch Valley crop and to people who grew up eating it. Somebody else's medium is a different thing, and neither of us is lying.
Where the heat actually is in the pod
Heat comes from capsaicinoids, and the single most repeated piece of wrong information about chile is where they're made. It isn't the seeds. NMSU's guide to growing chile peppers puts it flatly: the compounds come from "glands normally associated with the placenta in the center of the pod where the seeds are produced," and "seeds are NOT sources of pungency, although they may absorb some of these capsaicinoids when cooked."
That last clause is the part worth keeping. Scraping the seeds out of a raw pod doesn't remove much heat, because you're throwing away the passengers and leaving the driver. Pulling the white pithy placenta out does. And once the pod has been cooked, the capsaicinoids have moved around inside it, which is why roasted chile doesn't respond to seed-picking the way a raw jalapeño does.
The numbers, variety by variety
NMSU has been releasing chile varieties for over a century, and in 2023 the university published average heat levels for all of them in Circular 706, by Danise Coon, Stephanie Walker, Dennis Lozada, Ivette Guzman and Paul Bosland. Here's what those figures look like grouped into the bands people actually shop by.
Two things in that list are worth a second look. The first is that the heritage selections run consistently hotter than the varieties they were selected from: Big Jim averages 6,500 and NuMex Heritage Big Jim averages 9,500, while Sandia averages 6,500 and NuMex Sandia Select averages 9,500. The pod looks the same and the sign at the roaster says the same thing, but the published average is half again as hot.
The second is the ceiling. People come to New Mexican chile expecting something in the neighborhood of a superhot, and the published averages for this pod type simply don't go there. The NMSU Chile Pepper Institute's own figures put the Trinidad Moruga Scorpion at 2 million SHU. Hatch chile is a different kind of thing, and its whole point is that you can eat a plate of it.
Why a mild variety turns hot
Here's the part that explains the jar you bought last year that wasn't like this year's. Genetics set the range, and the season decides where inside that range the crop lands.
NMSU's guide to measuring chile pepper heat, by Paul Bosland and Stephanie Walker, states the mechanism in one line: a mild variety "will become hotter when exposed to any type of stress in the field," and a hot variety given good conditions "will become only moderately hot." The stresses that count, per the garden guide, are water (too much or too little), temperature (too cool or too hot), disease and insect pressure.
Circular 706 says the same thing about its own table, which is the honest and slightly inconvenient caveat on every number above: "Genetics, weather, growing conditions, and fruit age affect capsaicinoid content and thus the heat level," and the listed figures "are averages that can vary by year and growing location." NMSU's chile facts site goes further and says heat can fluctuate "from pod to pod on the same plant."
Put those together and you get the real answer to why your green chile stew tasted different this year. A dry, hot stretch in July will push a field of a mild variety up into medium territory, and a kind season will pull a hot variety back down. Nobody in the valley is changing the recipe. The weather is.
What our heat levels are, by format
We spec heat by format, and the two formats don't offer the same set. That trips people up often enough that it's worth laying out plainly rather than making you click through three product pages to work it out.
So the choice in front of you isn't really mild against medium against hot. It's which format you want, and then which of the two or three heats that format carries. If you want mild, you want the freezer. If you want medium, you want a jar. Nobody planned it as a puzzle and it's worth saying out loud.
One more thing about our jars specifically, because it bears on heat. What goes into them is a blend of chile from around the valley rather than a single named variety, which is deliberate: blending across fields is how you hold a heat level steady when, as above, any one field's heat depends on how that field's summer went. It also means we can't tell you that your jar is Sandia or Big Jim, because it isn't only one of them.
Which one to order
That last one is what I'd actually do, and I'd do it every time over trying to find a single heat that suits four people. Cooking to the lowest tolerance in the room and putting the hot jar on the table costs you nothing and it ends the argument. A pot cooked to somebody's limit can't be walked back.
When to buy somewhere else
If you're in New Mexico in late August or September and you can get to a roaster, go to the roaster. Not because of what it costs, but because that's the one situation where you can ask for a variety by name. You can stand there and say Big Jim or Sandia or Barker's and get exactly that, which is a degree of control no jar on any shelf can give you, ours included. Our chile is blended across the valley on purpose, and blending is the opposite of picking your variety.
The same goes if you want to taste the difference between a heritage selection and its parent, or if you want your green chile at the specific stage of ripeness you prefer. That's a harvest-season, in-state, standing-in-a-parking-lot activity, and it's one of the better things about living there. If that's your September, spend it that way, and read how much a sack actually weighs before you go so you buy the right amount.
For the other eleven months, or if you're one of the many New Mexicans who no longer lives in New Mexico, the frozen chile is the version of that with the labor and the timing taken out. It's peeled, flame roasted and flash frozen, it's grown in the Hatch Valley and harvested once a year, and as the product page says, when it's gone it's gone until next September.
Turning the heat down in a dish
If you've overshot, the fix isn't water. Capsaicinoids don't dissolve in it, so a glass of water spreads the burn around and moves on. Dairy works better, and peer-reviewed sensory research at Penn State has found that it's the proteins in milk doing much of that work rather than the fat alone, which is why skim milk performs about as well as whole.
In a pot, the practical moves are volume and fat. Add more of everything else, stir in sour cream or cheese, or serve it over something starchy. For a green chile enchilada sauce that came out hotter than you wanted, a little more stock and a little more cheese on top will do more than any amount of scraping. And with a cheese-heavy dish, the heat reads lower to begin with, which is worth knowing when you're picking which recipe to use the hot jar in.
Going the other way is easier. If your medium isn't doing enough, you don't need a hotter jar so much as more of the one you've got, and draining the liquid off first concentrates what's there.
Questions we get
How hot is Hatch green chile on the Scoville scale?
The New Mexican pod type varieties released by NMSU average between 0 and 9,500 Scoville heat units, according to the university's 2023 Circular 706. Most of what gets sold as green chile sits in the 900 to 6,500 range. NMSU notes that these are averages that vary by year and growing location.
Is Hatch chile hotter than a jalapeño?
Usually not, though it depends entirely on which variety and which season. The published NMSU averages for New Mexican pod types top out at 9,500 SHU, and no New Mexican pod type in Circular 706 averages above 10,000. Hatch chile is generally a chile you eat by the bowl rather than by the slice.
Why was my green chile hotter last year?
Because the weather was different. NMSU's Guide H-237 states that a mild variety "will become hotter when exposed to any type of stress in the field," including water stress, temperature extremes, disease and insect pressure. Circular 706 confirms that weather and growing conditions change capsaicinoid content from season to season.
Does taking the seeds out make chile less hot?
Barely. NMSU's Guide H-240 states that "seeds are NOT sources of pungency," and that the capsaicinoids come from glands associated with the placenta, the pale pithy tissue in the center of the pod. Removing that tissue reduces heat. Removing seeds mostly doesn't, though cooked seeds do absorb some capsaicinoids from the pod around them.
What heat levels does Chopped Chile Co. sell?
Our 16 oz jars of green and red chile come in Medium and Hot. The red and green harvest blend comes in Medium only. Our frozen green chile comes in Mild, Hot and XXHot, in 10 and 20 pound sizes. There's no mild jar and no medium frozen.
Is the word hot on a chile label regulated?
No. USDA grade standards for peppers other than sweet peppers cover maturity, shape, size, color and damage. Pungency isn't in them. The New Mexico Chile Advertising Act regulates where the chile came from and says nothing about how hot it is. Every heat label you read is the seller's own scale.
Which heat level should I order first?
A jar of Medium green chile if you're new to it, Hot if you grew up eating it, and frozen Mild if you're cooking for children. If the household disagrees, cook with Medium and put a jar of Hot on the table.
The short version
Heat levels on chile are seller's scales, not measurements, because nobody grades chile for pungency. The published NMSU averages for New Mexican varieties run from 0 to 9,500 Scoville heat units, the heat lives in the placenta rather than the seeds, and a field's weather can move a mild variety up and a hot one down within the same season.
On our end: jars are Medium and Hot, the blend is Medium, and frozen is Mild, Hot and XXHot. Start at Medium if you don't know, go Hot if you do, and keep a hot jar next to the stove either way. If you want more to cook with it, there's a recipe book and an eBook version, and if you're looking for us on a shelf near you, the store locator has the current list. Restaurants and retailers buying by the case should start at wholesale.