How to store anchovies in oil: complete step-by-step guide

Why preservation is key

Properly preserving anchovies is not a minor detail: it determines whether a good tin remains good on the second day or becomes a disposable product. Salt-cured anchovies are stable for months thanks to three factors: high salinity, low water activity, and oil that prevents contact with oxygen. If you alter any of these three, deterioration dramatically accelerates.

You pay €15-40 for a premium tin and then leave it open in the fridge. Three days later it smells off, the fillets darken, and the oil has a metallic taste. It's not the product — it's the storage. The good news is that proper preservation is very simple if you understand what to avoid.

Before opening: unopened tin

A hermetically sealed tin of anchovies is very resilient. Optimal conditions:

• Temperature: between 12 and 18°C. Ideally a cool pantry. Some purists refrigerate them at 4°C; it's not necessary but doesn't harm either.
• Light: darkness. Direct light can oxidize the oil through transparency (in glass jars).
• Humidity: low. Metal tins can externally oxidize in humid places. Exterior oxidation does not affect the content, but it aesthetically spoils it.
• Position: horizontal preferred. Keeps the fillets covered by oil at all times.
• Duration: 12-24 months from packing. Check the best-before date. Some preserves improve during the first year.

A properly stored tin can last perfectly until the end of its best-before date. Some canneries (Codesa, La Cántabra) even certify longer periods under controlled conditions.

After opening the tin: step-by-step

This is where 90% of mistakes are made. The rule is radical: once the tin is opened, all fillets must be transferred to a glass container.

1. Prepare a clean glass jar with an airtight lid. Appropriate size for the remaining fillets — there should be as little air as possible.
2. Place the remaining fillets one by one in the jar. If you wish, intersperse a bay leaf or a raw garlic clove.
3. Cover completely with EVOO. No fillet should be exposed. The oil should be at least 0.5 cm above the last layer.
4. Seal, label with the date, and refrigerate between 2 and 8°C.
5. Consume within 3-4 weeks. When removing fillets to use, ensure the remaining ones are still covered with oil.

You can use the oil from the original tin: add it to the jar or use it for cooking (mix with fresh EVOO to extend). If it was olive oil or EVOO, it is perfumed by the anchovy and is excellent for finishing dishes.

Anchovies in salt "for cleaning": long-term preservation

Anchovies "in brine" or "for cleaning" are those that come whole (not filleted), covered in dry salt, sold in large tins or in bulk. They are the professional format used by restaurants and enthusiasts who want to clean the product before eating.

Their preservation is radically different from anchovies in oil:

• Duration: 3-5 years (yes, years) if kept covered in salt.
• Storage: in their original tin or jar. Cool and dry place. DO NOT refrigerate (the humidity of the refrigerator can liquefy the salt and degrade the product).
• If the salt level drops: add more coarse sea salt until they are covered again.
• Before eating: wash, remove skin, central bone, side bones, and preserve in EVOO in the fridge for 3-7 days, or consume immediately.

This is the professional way to buy anchovies: they last a long time, you prepare them yourself to your liking, and you ensure they are perfectly cured.

Can they be frozen?

Technically yes, but it is not recommended. Salt-cured anchovies do not need freezing for preservation, and freezing introduces problems:

• Fats crystallize and upon thawing, the fillet loses texture.
• The oil changes state and can separate.
• The flavor loses aromatic nuances.

Exception: anchovy compound butter does freeze well (form into rolls in film and freeze for up to 3 months). And homemade marinated anchovies (boquerones en vinagre) can be frozen for 24-48 hours to eliminate anisakis before marinating, but that is a food safety case, not preservation.

8 mistakes that ruin good anchovies

1. Leaving the metal tin open in the fridge. The metal of the container oxidizes the fillet on contact. A metallic taste appears within 24 hours.
2. Not completely covering the fillets with oil. The part exposed to air oxidizes and dries out.
3. Using refined or sunflower oil for preservation. Only EVOO or olive oil. Sunflower oil does not preserve as well and provides a neutral flavor.
4. Plastic jar. Only glass. Plastic absorbs odors and can release microplastics in hot oil.
5. Handling with unwashed fingers. Introduces bacteria and shortens shelf life. Always use clean tongs or a fork.
6. Mixing batches in the same jar. Each purchase can have different saltiness and curing. Mixing shortens shelf life and unbalances the flavor.
7. Refrigerating anchovies in salt. The humidity of the refrigerator damages dry preservation.
8. Storing an open tin for more than 1 hour at room temperature. Dairy products or anchovies in oil are not as delicate as fresh fish, but heat accelerates oxidation.

Signs they are spoiled

• Smell: intense fishy, sour, ammoniacal. A good anchovy smells like "cured cheese," not fish.
• Color: very marked darkening (grey-greenish) instead of the characteristic reddish-brown color.
• Texture: disintegrated, soft fillet that breaks upon touching.
• Oil: cloudy, thick oil or with white sediment.
• Taste: metallic, rancid, bitter taste. A good anchovy is salty + umami. Period.
• Bubbles or pressure in the tin: never consume. Indicates bacterial fermentation. Discard.

When in doubt, discard. Food poisoning from fish is not worth saving a tin.

Preserving homemade anchovies

If you have bought anchovies in salt "for cleaning" and filleted them yourself:

1. Wash briefly under cold water to remove excess external salt.
2. Dry with a clean cotton cloth. Important: dry fillet before oil.
3. Transfer to a glass jar, layering the fillets.
4. Cover with EVOO until it surpasses the last fillet.
5. Optionally add aromatics: bay leaf, garlic, peppercorns. Don't overdo it.
6. Seal and refrigerate.
7. Wait 24-48 hours before consuming. The oil penetrates and softens the fillet.
8. Duration: 2-3 weeks in the fridge.

Frequently asked questions

Conclusion

Properly preserving anchovies is ridiculously simple: glass jar, EVOO completely covering the fillets, airtight lid, and fridge. If you do that, a premium tin lasts a month in perfect condition and you make the most of every fillet. If you leave the open tin in the fridge, you're not preserving — you're letting it slowly spoil.

And a final tip: buy the format you will consume. If you open a 50g tin, you'll eat it in 2-3 days without transferring. If you open a 200g tin and won't finish it in 3 weeks, two smaller tins are better. Formats are designed for different consumption patterns.

— Maria José Sáez Pastor
Cook with Catalan and Cantabrian tradition. Has been cooking with Cantabrian anchovies for 30 years.

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