Polish herring in oil with onion: soaked in milk, layered in a jar, ready after a day
The simplest home-made herring: matjes fillets soaked in milk to give up their excess salt, layered with thin onion, allspice and bay leaf and covered with oil to the very top. Nothing is cooked, the work takes twenty-five minutes, and a day in the fridge does the rest. With hot potatoes and dill, or with bread and butter.
Your own work in that: 25 min.
- Soaking in milk 240 min
- Packing the jar 25 min
- Maturing in the fridge 1440 min
Step by step
0 / 6 doneSoak the herring in milk
Rinse the fillets under cold water and cover them completely with milk. Refrigerate 4 hours; very salty fillets can need up to 12 hours, tub matjes only 2. After soaking, cut off a piece and taste it: it should be lightly salted, not as salty as seawater.
Ingredients: 500 g matjes herring fillets · 500 ml milk
TipMilk draws out salt just as water does, and it also softens the fishy smell and gives the fillets a mild flavour — which is why many Polish homes soak herring in milk. If you prefer water, change it once or twice during soaking.
Four hours in milk, then a taste testDrain and dry
Lift the fillets out of the milk, rinse under cold water and pat dry on both sides with paper towel. Cut across into pieces 3 cm wide. Water that gets into the jar shortens the herring's life and turns the oil cloudy.
Patted completely dry, 3 cm piecesSlice the onion
Cut the onions into very thin rings, ideally on a mandoline. Thin onion takes on the oil and softens over a day; thick onion stays raw and sharp. If the onion is very pungent, cover it with boiling water for a minute and dry it.
Ingredients: 2 pcs red onions · 300 ml rapeseed oil · 8 pcs allspice berries · 3 pcs bay leaves · 10 pcs black peppercorns · 1 tsp sugar
Rings as thin as paperBuild the layers
Put a few onion rings, allspice, peppercorns and a bay leaf in the bottom of a scalded and completely dry jar. Alternate layers of herring and onion, tucking the rest of the spices between them, and press gently so no air pockets remain. Leave 2 cm free below the rim. For milder herring, sprinkle a teaspoon of sugar between the layers.
Herring, onion, spices, no air pocketsCover completely with oil
Pour the oil in slowly, tilting the jar so the air escapes, until it covers the top layer by half a centimetre. Tap the jar on the counter and check after a minute: if any piece of herring or onion is sticking out, add more oil and push it under with a spoon.
TipThe oil protects the herring from drying out and from the air, but it does not preserve it — the salt and the cold of the fridge do that. A piece standing above the oil dries, darkens and spoils first. The rule is simple: nothing may stick out above the oil.
Oil half a centimetre above the top layerWait a day
Close the jar and refrigerate 24 hours; after two days it is better still. Store in the fridge only, at 4 °C or below, and eat within 5 days. Always take pieces out with a clean fork and make sure the rest stays under the oil. Serve with hot potatoes and dill.
Ingredients: 800 g potatoes · ½ bunch dill
TipSalted herring is not a shelf-stable preserve and the oil does not pasteurise it: this is a fridge preserve, not a pantry one. A jar left out overnight belongs in the bin, however good it looks.
A day in the fridge, then potatoes with dill
Before you start
With apple and sour cream
Drain the herring from the oil and mix with one coarsely grated tart apple, the onion from the jar and 200 g of sour cream with a teaspoon of sugar. Herring in cream the next day, from the same jar.
With sun-dried tomatoes
Add 50 g of sun-dried tomatoes in strips and a sliced garlic clove between the layers, and use olive oil instead. A Mediterranean-style version, excellent with bread; because of the garlic in oil, keep it in the fridge only and eat within 4 days.
Too salty
Soaked too briefly, or the fillets came from a barrel rather than a tub. Lift them out of the oil, cover with fresh milk for 2 hours, dry and repack in a clean jar with fresh oil.
