CellarCure

Case Hardening in Salami: What It Is and How to Prevent It

Last updated November 2, 2026.

You slice into a salami that's been hanging for weeks. The outside ring is dark and firm. The middle is soft, pale and still kind of wet. That's case hardening, and it's worth taking seriously.

What case hardening is

Case hardening (also called crusting) is "the presence of a dry outer layer on the sausage while the interior remains tender" (IRTA, Sensory Defects in Fermented Sausages). It happens when the surface dries faster than water can move out from the center. IRTA puts it this way: "When surface drying occurs too quickly, water migration from the interior is insufficient to offset the surface dehydration, and if this persists, a dry crust forms in which water diffusion is slower" (IRTA, Sensory Defects in Fermented Sausages).

So the crust doesn't just look bad. It slows down the very drying you need. BCCDC says too low a humidity "could cause crusting on the surface and thus harm the internal drying of the sausage meat" (BCCDC 3.13).

Illustration, not a photo: a salami cut in half and seen end-on. A dark, dry ring runs around the outside edge, labeled dry outer ring. Inside it, the lighter center is labeled moist center.dry outerringmoistcenter
Case hardening, cut open. Illustration, not a photo: a dark, dry ring around the outside and a softer, wetter center.

Why it matters for safety

This part's serious. Dry salami relies on drying, along with fermentation and cure, for its safety. BCCDC explains that fermentation, curing agents and drying together result "in acidic pH and low water activity that provides process control for product safety," and that dry sausages are dried after fermentation "to reduce aw to 0.9 or below" (BCCDC 3.13). A crust that keeps the center wet works against that.

If the center never dried properly, don't eat it.

What causes it

The two big causes are humidity that's too low and air that moves too fast.

  • Low humidity. BCCDC's drying guidance notes: "above 80% moulds may grow; below 65% case-hardening may occur" (BCCDC 3.13). Elsewhere it says humidity "may be lowered later for removing moisture but not drop below 60%" (BCCDC 3.13).
  • Too much airflow. BCCDC says airflow should be managed "to prevent case hardening (if air flow is too great) and wild mould growth (if air flow is too low)" (BCCDC 3.13).
  • Recipe factors. IRTA notes that "lower salt content increases the risk of case hardening," and that high-pH meat gets harder as it dries, "making it more prone to case hardening" (IRTA, Sensory Defects in Fermented Sausages). That's one more reason to hit your pH target during fermentation (see How to make salami at home).

How to prevent it

Everything here comes back to drying the outside no faster than the inside can keep up.

  1. Start humid and come down slowly. BCCDC says relative humidity "should be initially set at 95% and then kept 5% less than the product, dropping with the product as it dries" (BCCDC 3.13).
  2. Stay in the drying range. BCCDC gives "a humidity of 60-90% for drying all cured meats" with "an ideal range of 75-80% at the beginning of the process" (BCCDC 3.13).
  3. Keep the fan gentle. You want some air movement, since too little invites wild mold, but not a gale (BCCDC 3.13). We don't give a fan speed because none of our sources give one for home chambers.
  4. Measure, don't guess. BCCDC expects drying rooms to have humidity controllers and a fan, and operators "to monitor relative humidity, the products, and adjust relative humidity accordingly" (BCCDC 3.13). A cheap hygrometer and a weigh-in log help. Our drying tracker does the weight-loss math.
  5. Check the salami, not just the gauge. A ring that feels hard and leathery early on while the center is still soft is your cue to act.

What to do if it's already happening

IRTA's advice if case hardening shows up: "i) increase relative humidity to promote product uniformity; ii) reduce air speed to limit external transfer; and iii) lower the temperature to reduce external transfer, limit undesirable microbial growth and increase equilibrium moisture content" (IRTA, Sensory Defects in Fermented Sausages).

In plain terms: raise the humidity, turn down the fan, and give the link time to even out. Some people vacuum-seal a crusted salami to let moisture redistribute. To be clear, none of our sources cover that trick, so we're not recommending it here.

Since a crust can harm the internal drying (BCCDC 3.13), we wouldn't trust the scale alone on a batch that looks crusted. To be clear, that's our call. Cut one open and check the center before you call it done.

If the center never dried properly, don't eat it. When in doubt, throw it out.

Sources

Read our disclaimer. This page is general education, not professional food-safety advice.

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