The way to keep chili flakes and paprika from molding is to store both in a completely dry, airtight container, in a cool cabinet away from light; oil-rich chili flakes in particular are more prone to mold once they pick up moisture than most other spices. Paprika contains no oil, so it usually lasts longer, but it can still clump in a damp spot and pick up the same risk over time.
Why do chili flakes mold faster?
Homemade or naturally dried chili flakes can carry a small amount of residual oil and moisture, and unlike a powdered spice, that residue creates a good surface for mold to grow. Every time a jar lid is opened and closed, ambient humidity gets a chance to enter the container and adds to that risk.
If store-bought chili flakes look oily and glossy between the flakes, that is a sign of higher moisture content, and the jar should be used up sooner. Chili flakes bought loose from an open bin can carry even more moisture than a packaged product, so transferring loose flakes into a dry container as soon as you get home matters even more.
What container and temperature are right?
A dark glass jar or a metal spice tin protects better than a plastic bag, since it blocks light and resists moisture better. The ideal storage temperature is 15-20°C; a shelf right above the stove is one of the worst spots because of the heat and steam. Choosing a tin with a rubber-sealed lid that closes fully, rather than a loose-fitting one, keeps ambient moisture out as effectively as possible.
How long do they stay fresh?
Stored properly, chili flakes and paprika can be used for 1 to 2 years, but their strongest flavor is in the first 6 months; after that, the color fades and the flavor weakens. A batch that has turned brownish or dull is not unsafe, but it will not add much flavor anymore. If a pinch rubbed between your fingers gives off little to no scent, that is another sign most of the aroma has already faded.
How can you spot mold?
White or greenish spots on the inside of the jar, clumped and damp-looking patches, or a musty smell are all signs of mold. Never scrape off just the top layer of a moldy spice and use the rest; unseen mold threads can reach deeper into the container.
Should they be kept in the fridge?
Dry spices should not be kept in the fridge; every time the lid opens, humid air from outside enters the container, and that speeds up mold growth in oil-containing spices like chili flakes. A dry, dark cabinet at room temperature is always the safer choice.
A large bag of chili flakes can be split into smaller portions kept in a separate sealed container, so the main batch, opened less often, stays drier for longer. Writing the purchase date on the tin makes it easier to track that six-month flavor window.