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Fish and seafood from Alaska
Tepa are salmon heads left to age in a grass- or moss-lined pit or a barrel in the ground until they turn soft, then eaten. Health agencies note that the aging is mostly protein breakdown, not an acid fermentation, so the pH stays near neutral and Clostridium botulinum type E can make toxin. Sealed plastic or glass containers and warm aging raise that risk.
| Salmon heads | In 1877–1881 Nelson saw king salmon heads, taken in summer, aged in small pits[ak-guide] |
| Straw, grass or moss to line the pit, and turf to cover it | [ak-guide] |
Total time across the recorded steps: 10 min
What changes: Heads are cut from salmon caught in summer
Microbes at work in this step
Not documented for this step.
Measured measured in a studySet fixed by a specification or tested recipeReported one source reports itTypical a general value, not sourced for this fermentUnconfirmed not yet checked against a source
Tepa are salmon heads left to age in a grass- or moss-lined pit or a barrel in the ground until they turn soft, then eaten. Health agencies note that the aging is mostly protein breakdown, not an acid fermentation, so the pH stays near neutral and Clostridium botulinum type E can make toxin. Sealed plastic or glass containers and warm aging raise that risk. Made in 4 steps over 10 min. The longest step, boil before eating, takes 10 min (CDC 2026).
| Main step | 10 minReported[cdc-prev] | Boil before eating |
|---|---|---|
| Temperature | up to 2 °CReported[ak-guide] | Age until the heads are soft |
Nelson's account of tepa mentions no salt, rice or other starch. The Alaska guide says the aging is protein breakdown, not acid fermentation, so the pH stays near neutral. Surströmming, by contrast, relies on salt and chilling.
This page records a practice; it is not a recipe to follow. Alaska has a far higher botulism rate than the rest of the United States, and every Alaska case has been tied to traditional foods. Salmon heads were implicated in 14 of 141 confirmed outbreaks from 1950 to 2010, and type E caused 83% of all outbreaks. Sealed plastic, glass or bags keep air out and favour C. botulinum; warm aging in the sun or indoors speeds toxin formation. One experiment found no toxin in a grass-lined pit, but that does not make a pit safe; the Alaska guide says traditional preparation will not always prevent toxin. For people who keep this tradition, the state guidance is to use traditional methods, age at below 2 °C, wash hands and containers, and cook the food; CDC advises boiling home-fermented Alaska Native foods for 10 minutes before eating. Boiling is no guarantee, because the FDA says not to rely on heat as the control. CDC says the toxin cannot be seen, smelled or tasted, and that even a small taste can be deadly.
Hazards the sources name: Clostridium botulinum, mostly type E (salmon heads were implicated in 14 of 141 confirmed Alaska botulism outbreaks, 1950–2010).
Every number is labelled with how it is known. How this atlas is made
Edward Nelson saw king salmon heads aged in straw-lined pits in the Yukon–Kuskokwim district during his 1877–1881 visit; by autumn the heads were soft enough to knead into a paste. Shaffer and colleagues found in 1990 that preparation methods had changed over the previous 50 years in ways that may favour botulism.
