Red Pepper Flakes, Made From 25,000–50,000 SHU Cayenne

What goes into red pepper flakes?

Dried red chiles, crushed with their seeds. McCormick says its crushed red pepper comes from dehydrated and crushed red peppers, typically cayenne¹, and that it starts with whole, ripe peppers and uses set levels of seeds and pods².

1Crushed dried pod: typically cayenne¹2Seeds, crushed in with the pods²3Whole dried cayenne: 25,000–50,000 SHU³

1. Crushed dried pod: typically cayenne¹
2. Seeds, crushed in with the pods²
3. Whole dried cayenne: 25,000–50,000 SHU³

That fits how growers use cayenne: UF/IFAS says growers usually dry cayenne and use it as a ground powder or flakes³. Ground, the same pepper goes on the shelf as ground red pepper, which McCormick says also goes by the name cayenne¹.

So when you pick up a jar that says "red pepper flakes" or "crushed red pepper", both names mean one thing: a red chile, dried and broken into pieces. The USDA spec that government buyers use to order spices lists red pepper in ground, crushed and flake forms, with at most 10 % moisture⁴. That dryness is why the pieces snap between your fingers instead of bending, and why your jar keeps for months.

Do crushed red pepper and red pepper flakes differ?

Barely. McCormick, describing its own jars, calls red pepper flakes visually similar to crushed red pepper, with a finer texture, and says the flakes typically pack more heat¹. It gives no number for that extra heat, so we treat the two as the same pepper at two grinds.

Which one should you call hotter? Your own jar decides, and you find out by tasting a few flakes on your tongue, because brands crush to their own size and mix in their own share of seeds. McCormick says it tests each new crop for color, flavor, aroma and heat¹, which keeps one jar close to the last one from the same brand, not to a jar from another brand.

You can swap them one for one in your cooking. McCormick says crushed red pepper and ground cayenne come from the same chile, so you can trade one for the other¹. Powder packs tighter than flakes, so a level spoon of it carries more pepper: if a recipe asks for 1 teaspoon of flakes and you only have ground cayenne, start with half a teaspoon, taste, and add more.

What types of chile flakes can you buy?

Chile flakes is the wider name you will meet: any dried chile, crushed. Red pepper flakes usually means the cayenne kind from the pizza counter. NMSU's Chile Pepper Institute spells the plant and its fruit chile⁵, so "chile flakes" on a jar just points to the pod, and the label should tell you which one.

The pepper in your jar sets the heat, and the jump between branches can catch you out. A spoon of habanero flakes can carry 2 to 14 times the heat of the same spoon of crushed red pepper. Worked from the ranges: habanero runs 100,000–350,000 SHU and cayenne 25,000–50,000 SHU, so 100,000 ÷ 50,000 = 2 and 350,000 ÷ 25,000 = 14³⁶.

Regional flakes come from their own peppers. Aleppo and gochugaru each have an index entry with the pod behind them, and Urfa flakes come from a pepper of their own too.

Shichimi togarashi mixes chile with other seasonings, so the page on shichimi togarashi treats it as a blend, not a single pepper.

How hot do red pepper flakes run?

As hot as the pepper in them, and the jar may not say how hot that is: McCormick's crushed red pepper page calls it consistently spicy and gives no number². Even the USDA purchase spec for red pepper leaves its Scoville cell empty⁴.

So the cayenne range, 25,000 to 50,000 SHU³, gives you the best guide for a plain jar. If you like numbers you can feel, you can turn that range into a weight of capsaicin. The USDA spec sets 1 ppm of capsaicin equal to 15 Scoville units⁴, so cayenne at 25,000–50,000 SHU holds about 1,700 to 3,300 ppm, or 1.7 to 3.3 mg of capsaicin per gram.

A level teaspoon of ground cayenne weighs 1.8 g in USDA's data⁷, so it carries roughly 3 to 6 mg. A shake of flakes over your slice of pizza holds far less than that teaspoon, which is why a few pinches feel warm to you and a spoonful stirred into your pot of sauce feels hot.

What is pizza pepper?

Pizza pepper is the shaker of crushed red pepper you find on a pizzeria counter. McCormick names pizza, soups, salads and sauces as the foods it suits¹. Pizza seasoning is a different jar: the USDA spec builds it from parmesan, garlic, onion, red pepper, thyme, basil and oregano⁴, so it tastes of herbs and cheese first and heat second.

How do you make your own flakes?

Dry your hot peppers until they turn brittle, then crush them coarsely. Penn State's dehydrator method and grinding advice cover both halves⁸.

1. 1

   Glove up and cut

   Wear plastic gloves, then cut the peppers into 3/8-inch pieces or slices; you do not need to blanch them.⁸

2. 2

   Dry at 140°F, then 130°F

   Start the dehydrator at 140°F for 2 hours, then lower it to 130°F until the pieces feel tough to brittle.⁸

3. 3

   Cool and condition

   Cool the pieces, then keep them in a loosely covered jar two-thirds full for 4–10 days, shaking it daily. Beads of moisture inside mean the batch goes back on the trays.⁹

4. 4

   Crush and jar

   Pulse the dried pieces briefly in a blender for flakes; keep going for powder. Store airtight and dark.⁸

No dehydrator? Penn State says you can slit small hot peppers, thread them through the stems with a large needle and heavy thread, and hang the string where air moves freely; a string takes 3 to 4 weeks to dry⁸.

A blender and two jars carry a batch from dried pods to a shaker, and here is what each one does.

The full method, with which peppers make the best flakes, sits on the page for making red pepper flakes.

How long do red pepper flakes last?

About 6 to 12 months for homemade flakes stored airtight in a cool, dry, dark place; Colorado State gives that shelf life for well-stored dried vegetables⁹. For store-bought jars, McCormick says dried herbs and spices typically last 1 to 2 years¹, and Kansas State's pantry chart gives ground spices 2 to 3 years at 70°F¹⁰.

Those dates measure flavor, so your old jar rarely turns unsafe; it just tastes of less. Kansas State tells you to check the aroma and replace a spice once it fades, and notes that the freezer extends shelf life¹⁰. Light fades dried peppers quickly, and the fridge or freezer keeps their color best⁸. Heat shortens the clock too: the National Center for Home Food Preservation says the warmer you store dried food, the shorter it keeps¹¹.

What goes wrong with a jar of flakes?

Most problems come from light, heat or steam. Here is what each one looks like in your jar and what you can do about it.

• The flakes turned orange-brown. Light did it; dried peppers fade quickly in it⁸. They still work, with less color and aroma. Move the next jar into a dark cupboard.
• The flakes stuck together in clumps. They took in moisture, often from shaking the jar over a steaming pot. Dried food that picks up water again can spoil¹¹, so pour from the jar into your palm, away from the stove.
• They smell of nothing. The aroma has gone, and Kansas State's rule is to replace a faded spice¹⁰. The first whiff of a fresh jar sets your nose tingling¹.
• You see fuzz, or the jar smells musty. Throw it out; NDSU says to discard dried food that smells off or shows mold¹².
• Your homemade flakes went soft in the jar. They went in before they dried through. Dry until tough to brittle and condition them for 4–10 days first⁸⁹.

Which flakes should you reach for?

Match the jar to your dish and to how much heat your table likes. These are the calls we make from the source pepper's range.