Don’t fret if you don’t have the crushed red pepper flakes that your recipe calls for. You probably have something in your pantry that can take its place.
Best Substitute: Dried Peppers
Crushed red pepper flakes are nothing more than dried peppers (usually chili or cayenne) that have been ground up just enough to leave you with a mix of flakes, seeds, and ground pepper. So, if you happen to have some dried peppers in your pantry, it’s really easy to make your own pepper flakes. Just grab a couple dried peppers; remove the stems; then, give them a quick whirl in your food processor. Now, you have homemade crushed red pepper flakes to put to use in your recipe.
That’s really all there is to it.
One thing to keep in mind: Different peppers have different levels of heat. So, if you want a good flavor match, try to use a pepper that’s similar in heat to a cayenne. If all you have is really hot dried peppers, don’t sweat it. Just use fewer pepper flakes in your recipe to compensate for the difference.
When working with hot peppers, it's smart to wear gloves. The capsaicin that's responsible for giving peppers their heat can be irritating if you get it on your skin or in your eyes.
Good Substitute: Ground Cayenne Pepper
Since ground cayenne pepper is made from the same pepper as crushed red pepper flakes, it also makes a good substitute. Use 1/2 to 3/4 as much ground cayenne to achieve the same level of heat. I recommend starting with the smaller amount and adjusting up for taste. It's easier to add heat than it is to take it away.
Still Good: Chili Powder
If you don’t have dried peppers or ground cayenne pepper in your pantry, use chili powder. It isn’t nearly as hot, but if you double the quantity called for, it’ll get the job done.
In a Pinch
If you don't have any of these other things on hand, just grab a bottle of hot sauce from your pantry, and add a few splashes to your recipe. Since the heat level of hot sauce can vary widely, it's best to start with a small amount; give the dish a quick taste, and then add more as needed.
Hot or cocktail sauce may be the best substitute if you're cooking for some people who like spicy foods, and some who don't. It's something that can be added to the table to customize the heat level, so everyone is happy, including the cook.