KO EN Finnish Main course⏱ 410 minEdit history

Kalakukko (Fish and Pork Baked in a Rye Crust)

Name: Kalakukko (Fish and Pork Baked in a Rye Crust)
Prep time: 1 h
Cook time: 5 h 50 min
Total time: 6 h 50 min
Yield: 6 servings
Cuisine: Finnish
Ingredients: 500 g wholemeal rye flour; 250 ml water; 10 g salt; 1 kg small freshwater fish; 300 g pork belly; 20 g salt; 1 tsp peppercorns; 60 g butter

The dish of Savonia in Finland: small freshwater fish, bones and all, sealed with pork belly inside a rye crust and baked for six hours. Pastry is meant to come out of the oven crisp; this crust is the opposite. It is there to be a pot, and to hold the fish’s own liquid in for six hours. What those six hours do is the point of the dish: the bones of a small fish go soft enough to eat. Leaving them in is design rather than laziness.

Ingredients

6servings

The rye crust (serves 6)
wholemeal rye flour · see the tips500 g
water · lukewarm250 ml
salt10 g
The filling
small freshwater fish · vendace, perch or roach; the bones stay in1 kg
pork belly · sliced thin; use less salt if it is already salted300 g
salt20 g
peppercorns · optional1 tsp
To serve
butter · at room temperature60 g

Steps

Work the rye flour and salt with lukewarm water into a stiff dough. No fat goes in — a short dough cannot survive six hours and cracks, and then the liquid is gone. Knead three or four minutes and cover it for twenty.
⏲ 20 min
Pat the dough out into an oval about 1cm thick. Do not roll it: rolled rye dough cracks.
⏲ 10 min
Gut and rinse the fish. Leave the bones in. Trim the gills and fins and that is all. Salt and pepper them.
⏲ 30 min
Layer the fish and the pork belly into the middle of the dough, leaving about 3cm clear round the edge.
⏲ 10 min
Bring the dough up over it, pinch the seam hard and tuck it underneath. Smooth the whole surface with a wet hand so there is nowhere for a crack to start. This seal is half the dish.
⏲ 15 min
Bake at 250-275°C for 45 minutes to set the crust hard and colour it.
⏲ 45 min
Drop the oven to 130-150°C, wrap it in greaseproof and foil, and bake five hours more. If a crack appears, patch it at once with a paste of rye flour and water.
Rest it still wrapped for an hour. This is when the crust takes up the fish liquid and softens.
⏲ 60 min
Cut the top off like a lid and spoon the filling out with butter onto pieces of the crust, or cut the whole thing into thick slices.
⏲ 10 min

Tips & Variations

Variations

Which fish: vendace (muikku) is the Savonian standard, and perch and roach are both used. Large fish do not work in this dish — their bones will not soften in six hours.
Lanttukukko, lihakukko: the same sealed bake with swede or with meat instead. Kukko is the sealed-and-baked thing; kala is the fish.
Kuopio: as ko.wikipedia notes, the capital of Northern Savonia is the home of this dish and holds a kalakukko baking competition. They are sold hot at the Kuopio market square, where you buy a whole one and open the lid.
A little wheat in the rye: if a pure rye dough is too awkward, take it up to 20% wheat. It cracks more readily at that point, so the seam needs more care.
At the table: in Savonia it comes with milk or with beer. The beer in the photograph is that.

Tips

The crust is a pot, not a pastry. Pastry is meant to come out of the oven crisp — Cornish pasty puts a raw filling in and cooks it in its own water, meat pie and beef wellington cool their fillings precisely so the pastry does not get wet. A kalakukko's crust is there to get wet. It holds the fish's own liquid in for six hours, and then you eat the crust that soaked it up. What kedjenou says — that the seal is half the dish — applies exactly, except that here the pot is made of dough.
What the six hours do is the bones. A small fish's bones are calcium phosphate crystals held together by collagen. Long, moist, low heat turns that collagen to gelatin, and what is left is soft enough to chew and swallow (braising). That is why the bones stay in, and why it does not work with a big fish.
Why it has to be rye. As pumpernickel explains, rye carries pentosans — gums that hold up to eight times their weight in water. A rye crust can therefore sit wet for six hours without going to paste, and without drying out and splitting. Wheat builds gluten, which makes it easier to handle at the start and then sets and cracks in the oven (choosing flour).
No fat. Fat in a pastry is there to get between gluten strands and make it short (dough and gluten). A short crust is a disaster here.
Patch a crack the moment you see one. One split at hour two and all the liquid is gone; then the filling is baked fish and the crust is dry bread. Look at it each time the oven door opens.
Pat it, do not roll it. A rolling pin puts lines of stress into rye dough and those lines are where it cracks. The palm of your hand is the traditional tool.
The hour's rest is the last step. Straight out of the oven the crust is still hard. Wrapped for an hour, the inner crust takes up the liquid and softens, and that is when to eat it.