How to cure fish at home: salmon, herring and mackerel — safely and deliciously
Why fish for curing must be frozen first and at what temperature, and which fish shouldn't be cured at home. Dry-curing salmon and trout with sugar and dill (gravlax) in a day, herring and mackerel in brine, salt ratios, how to slice and how long it keeps.
Safety first: parasites
Curing doesn't replace cooking. Salt in home quantities over a day or two doesn't kill parasite larvae that can live in fish. So curing has one non-negotiable rule: the fish must be deep-frozen first.
Sea fish (herring, mackerel, wild salmon, cod) can carry anisakid larvae. Freshwater fish of the carp family (carp, bream, ide, roach) can carry liver flukes.
- Buy fish that has already been frozen — most salmon and herring are sold frozen.
- Freeze chilled fish for curing yourself: at −18 °C or colder for at least 7 days. The colder, the safer.
- Don't cure freshwater carp-family fish raw at home — a household freezer isn't reliable enough for them. Fry, bake or poach them instead.
- Pregnant women, young children and people with weakened immunity are better off not eating raw cured fish at all.
Which fish to choose
Oily fish cure best: salmon, trout, coho, sockeye, herring, mackerel. The fat keeps the flesh tender and stops it drying out in the salt.
Choose fillets with firm, springy flesh, bright even colour and a clean sea smell. Skin-on fillets are easier to cure — they hold their shape and slice more neatly.
Thaw fish slowly in the fridge, 12–24 hours. Fast thawing makes the flesh mushy. Remove pin bones with tweezers: run a finger along the fillet against the grain of the bones and they'll stick up.
Gravlax: dry-cured salmon
The simplest and most popular method. Scandinavian gravlax is salmon cured in a mix of salt and sugar with dill.
- Per 1 kg fillet: 40–50 g salt (2 level tbsp coarse salt), 20–25 g sugar (2 tbsp), 1 tsp crushed black or white pepper, a large bunch of dill.
- Salt to sugar is 2:1. More sugar makes it softer and more tender; less makes it saltier and firmer.
- Mix the salt, sugar and pepper. Sprinkle over the flesh, a little less on the skin. Top with chopped dill.
- Wrap tightly in cling film or put skin-side down in a container, cover and weigh down with a small weight (500 g–1 kg).
- Refrigerate for 24 hours for a light cure or 48 hours for a firmer one. Turn after 12 hours if it's in a container.
- Scrape off the dill and pat the fish dry with kitchen paper to remove excess salt and liquid. Don't rinse it with water — it goes watery.
Quick lightly cured fish
If you need the fish for dinner, cut the fillet into 2–3 cm portions or thin slices. Thin slices cure in 1–2 hours; 2–3 cm pieces in 6–8 hours.
The salt is the same but the time is shorter. For thin slices, sprinkle each layer with a 2:1 salt-sugar mix (for 300 g fish, 1 tsp salt and ½ tsp sugar), drizzle with lemon juice and olive oil and refrigerate for 1–2 hours.
Remember safety: fish for a quick cure must also have been frozen first.
Herring in brine
Herring is cured whole (with or without the head, gutted or not) or as fillets. Fatty Atlantic herring tastes best.
- Brine per 1 litre of water: 3–4 tbsp salt (70–90 g), 1.5–2 tbsp sugar, 3–4 bay leaves, 10 black peppercorns, 5 allspice berries, ½ tsp coriander seeds, 3–4 cloves.
- Bring the brine to the boil, boil for 2 minutes and cool completely.
- Lay the thawed herring in a glass or plastic container and cover with the cold brine so the fish is fully submerged.
- Keep whole herring in the fridge for 2–3 days, fillets for 12–24 hours.
- For spiced herring, add 1 tsp mustard seeds to the brine and 1–2 tbsp 9% vinegar once cooled.
Mackerel: in brine, smoky without smoke
Mackerel is cured like herring: whole for 2–3 days, in pieces for 12–24 hours in brine.
A popular "like smoked" method uses a brine with onion skins and tea. Per 1 litre of water: 3 tbsp salt, 2 tbsp sugar, 2–3 handfuls of onion skins, 2 tbsp black tea, a bay leaf and pepper. Boil for 5 minutes, cool and strain. Mackerel left in it for 2–3 days turns golden like smoked fish, with no smoke or additives.
Mackerel spoils faster than herring: keep it no more than 4–5 days.
Salt ratios: light, medium, strong
How salty the fish is depends on the amount of salt and the time. For dry curing, go by salt as a percentage of the fish's weight.
- Lightly cured: 3–4% salt, 24 hours. Tender and juicy, keeps 4–5 days.
- Medium: 5–6% salt, 36–48 hours. Firmer, keeps up to a week.
- Strong: 8–10% or more, several days. Keeps a long time but is soaked before eating.
- Example: 1 kg fillet at 4% needs 40 g salt and 20 g sugar.
How to slice and serve
Slice salmon with a very sharp long knife into thin slices at a sharp angle, almost parallel to the board, from tail to head, cutting the flesh off the skin. 20–30 minutes in the freezer before slicing gives thinner, neater slices.
Prepare herring: cut off the head, slit along the back, peel off the skin, lift the fillets off the backbone and remove the large bones. Cut across into 1.5–2 cm pieces.
Classic ways to serve: salmon on buttered rye bread with lemon, on blini with sour cream, in rolls and salads. Herring with boiled potatoes, red onion and sunflower oil, in "herring under a fur coat", on black bread.
Storage
Keep lightly cured fish in the fridge in a sealed container: salmon 4–5 days, herring in brine up to 7–10 days, mackerel 4–5 days.
Covered in vegetable oil, sliced salmon or herring fillets stay juicy longer — up to a week.
Cured fish can be frozen: salmon for up to 2–3 months, tightly wrapped in portions. The texture softens slightly once thawed, but the flavour holds. Thaw in the fridge.
Questions and answers
Do I really have to freeze fish before curing?＋
Yes, if it was sold chilled and never frozen. It's the only reliable home method to kill parasite larvae: −18 °C or colder for at least 7 days.
Why is my cured fish watery and soft?＋
It was thawed quickly, rinsed with water after curing, or had been refrozen before you bought it. Thaw in the fridge and only pat it dry after curing.
Can I cure fish without sugar?＋
Yes, but sugar softens the salt's bite and makes the flesh more tender. Without sugar, use a quarter less salt and shorten the time.
How do I cure fish roe?＋
Free the roe from its membrane and cover it with hot, strong brine for 10–15 minutes. Pre-freezing applies to roe too — it's safer to buy it already cured.
How much salt per 1 kg of fish for a light cure?＋
30–40 g salt and 15–20 g sugar per 1 kg fillet, 24 hours in the fridge.
More kitchen secrets
Sushi and rolls at home: restaurant-style rice, fillings and safe fish
Which rice to use and how to rinse it, the water ratio and seasoned vinegar, how to cool rice properly. How to roll maki and inside-out rolls that don't fall apart, which fish is safe raw, fillings without raw fish, baked rolls and storage.
Read the articleHow to assemble a cake at home: level layers, soaking syrup, smooth sides and drips
How to cut a sponge into even layers, how much soaking syrup each layer needs, why to pipe a dam and do a crumb coat, how to smooth a cake with a scraper, how much frosting a 20 cm cake needs, how to make chocolate drips, stack a tall cake and transport it in one piece.
Read the articleHomemade ice cream without a machine: rich vanilla, sorbet and banana ice cream
Two-ingredient ice cream with condensed milk, a classic custard-based vanilla, why ice crystals form and how to prevent them, sorbet with the right amount of sugar, frozen-banana ice cream, ice lollies and storage tips.
Read the article