Genoese fishing communities. The name may derive from dialect 'ciuppare' (to chop). The technique of making a soup from the day's unsaleable bony fish is common to all Mediterranean fishing cultures but the Ligurian version has documented roots from at least the 16th century.
Ciuppin is the Ligurian fish stew that preceded the Californian cioppino — Genovese fishermen who settled in San Francisco's North Beach in the 19th century brought the technique with them. In Liguria, ciuppin is made from the day's small, bony, cheap fish, cooked down to a purée and strained through a food mill to create a thick, deeply flavoured fish broth. It is served over toasted bread or alongside larger pieces of fish added for the final simmer.
The collapsed, strained fish creates a broth of extraordinary depth and body — gelatin from bones, concentrated fish flavour, olive oil richness, tomato acidity. It is one of the most flavourful uses of the cheapest raw materials in the Italian kitchen.
The base is a soffritto of onion, garlic, celery, and parsley in olive oil, with white wine and tomato added before the fish. The fish used are small, bony, or off-cuts — scorpionfish (scorfano), gurnard, sea robin, John Dory frames — chosen for their gelatinous, flavourful flesh rather than for serving at table. Everything is cooked together until the fish completely breaks down, then passed through a food mill (moulinet) to extract a thick purée-like broth, discarding the bones. Larger, presentable fish (sea bass, mullet, grouper) are added to this strained base for the final 10 minutes of cooking.
The food mill extraction is non-negotiable — don't substitute with blending and straining. The rotational pressure of the moulinet breaks down fish flesh while the screen separates bones and skin. Season the final strained broth aggressively — fish broth needs more salt than you think. A pinch of dried chilli (peperoncino) is traditional in Ligurian fish cooking.
Using only fillets — the bones and heads are the source of the soup's depth; skinless fillets produce thin, insipid broth. Skipping the food mill step — the whole point is extracting collagen and flavour from bony fish. Adding the fine fish too early — they overcook to mush before the flavour has developed in the broth. Not acidulating with white wine — the acid lifts and brightens the fish broth.
Slow Food Editore, Liguria in Cucina; Giorgio Locatelli, Made in Italy