Hot peppers are, of course, known for their heat, but could cooking peppers make them spicier than you’d expect? Is it cooking fiction or cooking fact that cooking peppers make them hotter? Like many things, it’s a little bit fact and a little bit fiction.
Cooking peppers in a dish does make the dish itself taste hotter. But there’s a diminishing return in play here. Super-long cooking times can actually make the peppers and the dishes they are in taste milder than expected. And technically, roasting a chili alone typically makes the pepper less spicy, not more.
We go into the why of it all below, as well as a few ways you can use cooking peppers to gain heat to your advantage. We also cover a few ways you can temper the unexpected additional heat that cooking chilies can bring to the table.
Why cooking peppers makes dishes taste hotter
Before we look at the relationship between cooking chili peppers and their heat, you should understand what makes chili peppers hot in the first place.
The source of the heat in peppers is the chemical capsaicin. Capsaicin is concentrated in the pepper’s placenta, but it is also distributed throughout the interior, including in the seeds. The placenta or pith is the white membrane that anchors the seeds of the pepper to its walls.
Cooking peppers makes dishes hotter because the peppers break down while cooking and releases more capsaicin into the dish. The spiciness is then spread out throughout the dish, so it gives the sensation of an overall spicier meal.
But the catch: An extended cooking time can then see the capsaicin dissipate in the process. Meaning: your dish will begin to become milder over time. The culprit is typically steam. Capsaicin is considered thermostable — meaning it won’t break down due to normal cooking heat (unless high heat grilling.) But it is considered steam volatile — meaning some capsaicin is removed from the dish from the steam while cooking. The longer the cooking (especially with high amounts of steam), the milder the dish can get.
Does roasting peppers make them taste hotter?
The same typically holds true for roasting peppers — chilies tend to lessen in heat when roasted. The roasting releases the chili’s oils and capsaicin, but in this instance the capsaicin isn’t then spread across the entire dish. The chili eaten alone, may taste milder.
Roasting chilies over a high-heat grill can also destroy capsaicin. It can reach temperatures where capsaicin does start to break down, again decreasing spiciness.
An outlier where the chili could taste hotter is if the membrane breaks down and release its capsaicin into the meat of the chili fruit. That’s more likely if the chili pepper is roasted whole, where, of course, the membrane and seeds aren’t removed.
Granted, roasting chilies over high heat release all sorts of other flavors within the peppers, often enhancing their smokiness and nuttiness. So, it’s not like the peppers become bland, just less spicy.
Tips to increase heat (or maintain it)
When roasting peppers, roast over high heat with the minimum amount of time needed. You want to get that char, but without prolonged time over the flame. The longer it cooks, the more capsaicin is released/destroyed that’s no longer within the pepper.
When cooking peppers as part of a larger dish with standard cooking times: Allow the chilies to cook amid all of the other ingredients for 5 to 10 minutes at minimum. The longer they have to cook amid all the other ingredients, the more capsaicin is released into the entire dish, making the entire meal hotter.
When cooking peppers as part of a larger dish with prolonged cooking times (particularly with a chance for a lot of steam): Review the recipe and see if there’s a way to add the chilies in a later stage. You still want to get them cooking with the other ingredients, but you want to limit a prolonged period where the capsaicin can dissipate.
Tips to lessen heat
There are several ways to cook peppers to lessen the heat. The first is simply to remove the placenta and the seeds before adding the peppers to your dish. Since the placenta is the hottest part of the pepper, excluding them can reduce the heat considerably.
Another way to cut the heat level is simply to cook the peppers for a longer time. Let the prolonged cooking occur, allowing the capsaicin to slowly dissipate.
You can also lessen the heat by including acidic ingredients or dairy in your dish. For more information on how to lessen the heat using ingredients, check out our article, How To Tone Down Spicy Food.