Eel Soup
(Hamburg.) Clean and cut into 2-inch pieces 2 pounds of eels. Add 1 pint of boiling water, salt, pepper, parsley, 1 carrot, 1 onion, and 1/2 cup of vinegar. Cook 20 minutes, then add 1 cup of finely sliced carrot, cooked in water until tender, and 1 cup of cooked peas, 2 quarts of white stock, parsley, some thyme, and sweet marjoram, one half of the eel broth and salt. Finally blend and add 1 cup of hot milk and the yolk of 1 egg and pour into a tureen over the eels. Pass with this a dish of stewed pears, as they do in Hamburg.
A two-stage soup: eels poached in a sharp vinegar court-bouillon, then served in a lightly thickened white stock. Most of the work is in the sequencing, and the last step is where it can go wrong.
- The hinge: the liaisonThe cup of hot milk and egg yolk must be tempered — whisk a ladle of hot soup into the yolk and milk, then return it to the pot off the boil. Anything above a bare simmer after that point will scramble the yolk and leave curds through the broth.
- Sourcing the eelThe European eel is critically endangered and trade in it is restricted; farmed eel or conger is the safer buy, though Japanese and American eel are also assessed as threatened. Fishmongers will skin and cut eel for you, which is worth asking for. Eel serum is toxic raw but the protein is destroyed by cooking, so the 20-minute poach is doing real work.
- White stockIn period cookery this meant an unbrowned veal or chicken stock, lightly seasoned and left pale. Any good light chicken stock works; keep it under-salted, since the eel broth will concentrate what is there.
- The vinegarHalf a cup to a pint of water is a sharp poaching liquid by design — it firms the eel and cuts its richness. Only half that broth goes into the finished soup, so the acidity lands moderate. The recipe does not specify a type; a plain white wine vinegar suits it better than a malt or cider vinegar.
- Cooking timesTwenty minutes suits thick 2-inch cuts of eel; thinner pieces are done in 10-12. The carrot and peas are added already cooked, so they need only to heat through — long simmering will grey the peas.
- AssemblyThe eels go into the tureen and the soup is poured over them, which keeps the pieces intact. Fish them out of the poaching liquid with a slotted spoon before straining the broth.
- The stewed pearsFirm pears simmered in water with a little sugar and perhaps a clove, served alongside rather than in the soup. In Hamburg the sweet-sour pairing is the point, not a garnish.
- YieldTwo quarts of stock plus the eel broth and vegetables gives roughly 6 to 8 servings as a first course.
Hamburger Aalsuppe is one of the north German kitchen's better-known dishes, and it carries a persistent folk etymology: the name is often said to come not from Aal, eel, but from the Low German aal meaning "all" — a soup of everything left in the larder, to which eel was later added to match the name. Whatever the truth of that, the surviving versions share the profile seen here: vinegar for sharpness, vegetables, herbs, and dried or stewed fruit served with or in the bowl. The sweet-and-sour balance is characteristic of the Hanseatic ports, where dried fruit came in as ordinary trade goods rather than luxuries.