Whether you mistook cayenne pepper for chili powder, habaneros for jalapeños—or simply misjudged how much heat you can tolerate—it's happened to all of us: your soup, sauce, or chili is way too spicy. The question is, can you, well, un-spice it?
Chiles are different from, say, salt and sugar. Whereas saltiness and sweetness increase with the amount of salt or sugar you add, a single tiny chile pepper can contain an astronomical amount of heat. This makes it easy to misjudge. But what can you do?
Taste As You Go!
But what does "taste as you go" actually mean? Good question! "Taste as you go" is an approach to cooking that says you should sample something at the beginning of cooking, toward the middle, and again right before you serve it.
It also means that, when adding a seasoning like salt or sugar or hot chiles (especially one where an excess is liable to ruin the dish), you should add that ingredient a little at a time, and taste it along the way to see if you need to add all of it or just a bit.
Remember, too, that it can take a minute or so for the flavors of whatever spice or seasoning you've added to fully permeate the food. So even if you do taste, if you taste too soon, you can still end up adding too much.
The theory is that if you taste as you go, you'll eliminate the majority of "I added too much whatever" problems and even when you occasionally slip up, you'll discover it before you actually serve it, thus giving you a chance to do something about it.
Diluting a Spicy Dish
But suppose, during the course of tasting as you go, you discover that your dish is, in fact, too spicy. This is better than discovering the mistake only after your guests are eating. Still, now you've got to fix it.
Adding sweetness will balance out heat, and certain kinds of fat will physically wash away the burning compound in chiles (called capsaicin). Neither of these is a complete solution, however, because they do nothing to reduce the amount of spiciness in the dish.
Thus, both these remedies are best used in conjunction with the one and only way of reducing the spiciness in a dish, which is: to dilute it.
Diluting means adding more of all the other ingredients in a dish as a way to reduce the relative amount of spiciness in it. Obviously, this is easiest with something like soup, stew, or sauce.
Of course, if you've added too much cayenne to the surface of a pork shoulder, and you discover the error before you roast it, you can simply scrape or even rinse it off. Rinsing your roast in the sink isn't an elegant solution, but it's better than the alternative. Nor, obviously, will diluting work in the case of a casserole that you've already baked—at least not if you want to keep it a casserole.
So, the principle with diluting a dish is you're going to double the volume of everything else in it while leaving the amount of spiciness the same. Why double? We're assuming that if you're trying to fix a dish, it's at least twice as spicy as you want it.
So, if it's chili, and the recipe originally called for two cans of tomatoes and a pound of ground beef, you'll add another two cans of tomatoes and another pound of meat, thereby cutting the spiciness in half.
If it's soup, add a second amount of stock, broth, or water, plus whatever meats, veggies, and noodles it calls for, in equal parts to what you started with.
Clearly, you're going to end up with a double batch of soup or chili. But it will be half as spicy as what you were trying to fix. If you can halve the amount of spiciness, we'll consider that a success.
Balancing the Heat
Once you've halved the spiciness, you can now start to tinker around the edges by balancing the remaining heat with other flavors and ingredients. Generally speaking, this means adding a dairy product or adding sweetness (or both).
Dairy products like milk and cheese contain a protein called casein, which binds to the capsaicin, thereby detaching them from your tongue so they can be washed down your throat. Of course, this merely moves the heat to another location in your body, but at least it soothes your mouth.
Sweet ingredients like sugar or honey will balance out spiciness. It's almost like by giving your tongue another flavor to think about, you don't notice the spiciness so much. It's still there, but it blends in with the sweetness. Just don't add too much sugar or you'll have a whole new problem on your hands.