Cullen skink

Cullen Skink is Scotland's answer to the seaside vibe: a thick, warming soup built on the distinctive flavour of smoked haddock. This dish is the ancestor of 'chowder' type soups, where thickening is done not by a flour roux, but by the natural starch content of the potato. The meeting of cold-smoked fish (Finnan Haddie) and creamy milk creates a rich emulsion that is both rustic and sophisticated.
🕒 Prep Time 15 mins
🍳 Cook Time 20 mins
Total Time 35 mins
🍽️ Servings 4 servings
🔥 Calories 340 kcal
🌍 Cuisine Scottish, British

Ingredients

Equipment Needed

  • Medium saucepan
  • Potato masher or fork
  • Slotted spoon

Allergen Information

⚠️ Fish
⚠️ Milk

Instructions

1

Place the fish skin-side down in a saucepan and cover with the milk.

Tip: The collagen in the skin dissolves during cooking, making the base stock tastier and fuller-bodied.
2

Slowly bring to the boil, then immediately remove from the heat and let stand in the hot milk for 5 minutes.

Tip: This is called poaching. Gentle heat treatment preserves the fish's juiciness, while high heat would dry out the muscle fibres.
3

Remove the fish from the milk (set the milk aside!), peel off the skin, remove any bones, and break the meat into larger chunks.

Tip: The fish is fragile now, handle with care.
4

In the rinsed saucepan, melt the butter and sweat the onion until translucent (do not brown).

Tip: Sweating over low heat brings out the natural sweetness of the onion without creating bitter burnt notes.
5

Add the diced potatoes and water to the onion. Cook covered until the potatoes are completely soft.

Tip: It is ready when the edges of the potatoes are starting to break apart.
6

Take out about half of the cooked potatoes, mash with a fork or potato masher, then return to the pot.

Tip: This step replaces flour thickening. The released starch granules bind the liquid, giving a creamy texture (viscosity).
7

Pour in the reserved smoky milk and stir gently. Warm through, but do not boil!

Tip: Boiling can curdle the milk proteins, making the soup texture 'grainy'.
8

Finally, add the fish pieces and let them warm through for a few minutes. Season with pepper (salt probably won't be needed due to the fish) and serve sprinkled with fresh chives.

Tip: The fish is already cooked, now we are just adjusting the temperature.

Recipe FAQ

Why did the milk curdle?
The smoked fish can be slightly acidic, or too vigorous boiling could be the cause. Always cook gently (simmering)!
What potato is best for it?
A high-starch, 'floury' (Type C) variety, because this breaks down easily, thickening the soup.

Ingredients

  • 400 g Smoked Haddock (with skin if possible)
  • 500 ml Whole milk
  • 300 g Potatoes (floury variety, diced)
  • 1 head Onion (finely chopped)
  • 30 g Butter
  • 250 ml Water (or the fish poaching liquid)
  • 1 bunch Chives or Parsley (for serving)
  • 1 pinch White pepper