Can You Reheat Fish?
Written by Jordan Morley · Reviewed against FSA/NHS reheating guidance · Last updated 28 October 2026
Yes, you can reheat fish — once only, until piping hot (75°C). Gentle, covered reheating keeps it from drying out.
What makes it safe (or not)
Reheating fish is safe under the standard rules: it must have been cooled within 2 hours of cooking, kept refrigerated, and be reheated to 75°C (165°F) throughout, once only. Fish is delicate, so gentle methods — a covered dish in the oven, or short microwave bursts — get it safely hot without turning it to rubber. If it smells at all off before reheating, bin it.
You can also check the calorie content of fish alongside its safety information.
Method by method: what the sources say
| Method | How | Source |
|---|---|---|
| Oven | 120°C, wrapped in foil with a splash of liquid, 15 to 20 minutes. Leave the foil off if the fish is breaded or battered | Healthline (19 Oct 2026); The Takeout (10 Nov 2025) |
| Hob | Low heat in a covered pan, or steam, for about 4 to 5 minutes | Healthline; The Takeout |
| Microwave | Low to medium power in 20 to 30 second bursts, flipping between. The Takeout advises against it: uneven heating, overcooking, and a smell that lingers. If you must, use a lower power or a sealed parchment or foil pouch | Healthline; The Takeout |
The cook's number versus the safety rule
America's Test Kitchen reheats thick fillets on a rack under foil in a 275°F oven (about 135°C) until the fish reaches 125 to 130°F (52 to 54°C), and says thin fillets are better not reheated at all but served cold. That is a number for keeping fish moist, not a food-safety temperature for leftovers: it is far below the 75°C that the council and manufacturer pages we read give (Bromley leaflet; Birds Eye). The Food Standards Agency's research page says leftovers should be reheated until steaming hot throughout to kill bacteria that may have grown. We therefore follow the UK rule for leftovers, and where fish would be ruined by it, we suggest eating it cold instead.
Which fish?
| Fish | Best approach | Basis |
|---|---|---|
| Thick fillet (salmon, cod loin) | Gentle covered oven reheat until steaming hot all the way through | Healthline; ATK for the covered method; the steaming-hot rule is the FSA's |
| Thin fillet | Eat it cold within 2 days, flaked into a salad | ATK says serve cold; 2 days is the Food Standards Agency's leftovers limit |
| Breaded or battered | Oven without foil so the coating is not steamed soft | Healthline |
| Fish pie or fish in sauce | See reheating fish pie | n/a |
The 'eat cold' option is safe only if the fish was cooled within 2 hours and kept in the fridge, and eaten within the 2-day UK limit (Food Standards Agency). Reheat once only.
Sources checked
Everything in the sections above was checked against these pages on 28 October 2026.
- Healthline: How to reheat leftovers (Mary Jane Brown; updated 19 October 2026, first published 5 December 2018) — fish: microwave bursts, oven 120C foil 15-20 min, pan 4-5 min; reheat once
- America's Test Kitchen: How to reheat fish (no date shown) — 275F oven rack foil to 125-130F; thin fillets serve cold
- The Takeout: Why reheating leftover seafood in the microwave is a major no-no (Creshonda A. Smith, 10 November 2025) — avoid microwave; foil or parchment pouch; smell lingers
- Food Standards Agency research report: Not reheating leftovers until steaming hot throughout (published 31 October 2023; not consumer guidance) — reheat until steaming hot throughout to kill bacteria that have grown
- London Borough of Bromley: Clostridium perfringens leaflet for food businesses (no date shown) — reheat to 75C (business leaflet)
- Birds Eye: Making the most of your frozen leftovers (no date shown) — about 75C for 2 minutes
- Food Standards Agency: How to chill, freeze and defrost food safely (page text 'Published 18 December 2017'; page metadata shows 2026 updates) — leftovers within 48 hours
How to reheat fish safely
- Take fish from the fridge (use within 2 days of cooking; sooner is better for quality).
- Cover it — a lidded dish with a spoonful of water keeps steam in.
- Reheat gently: Healthline suggests about 120°C wrapped in foil for 15–20 minutes (no foil if breaded), or short low-to-medium microwave bursts, turning once.
- Check the thickest part is piping hot — 75°C (165°F) — and the flesh flakes.
- Eat immediately; never reheat fish twice.
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Check Price →Fish: the other answers on this site
| Question | Short answer (links to the full page) |
|---|---|
| In pregnancy | Safe — with a few limits |
| Left out overnight | No — throw it away (limit about 2 h) |
| Past the date on the label | No — use-by means use by |
Common questions
Can you reheat fish in the microwave?
Yes — cover it, use medium power in short bursts, and check the thickest part is piping hot. The smell is stronger in a microwave but the safety is the same.
What is the best way to reheat fish?
Reheat covered (Healthline suggests about 120°C wrapped in foil for 15–20 minutes, or low-to-medium microwave bursts) until the thickest part is piping hot (75°C).
Can you reheat fish twice?
No — once only, as with all reheated food. Portion before reheating so nothing goes back in the fridge.
Can you eat fish cold instead?
Yes — if it was cooked, cooled promptly and refrigerated, cold cooked fish within 2 days is fine (flaked into a salad, for example).
Why does reheated fish smell so strong?
Healthline and The Takeout both note that reheating fish, especially in the microwave, can leave a strong smell; neither explains why. It is a quality issue. Wrapping the fish in a foil or parchment pouch keeps the smell in, says The Takeout.
How long can I keep leftover fish before reheating?
Within 2 days in the fridge is the NHS/FSA advice for cooked leftovers (the US USDA allows 3–4 days). Cool it within 1–2 hours of cooking and keep the fridge at 5°C or below.
Can I freeze fish instead of reheating it?
Yes. Cooled promptly and frozen in portions, it keeps for around 1–2 months for best quality (USDA FoodKeeper), and stays safe beyond that. Defrost in the fridge, then reheat once until piping hot. See our freezing guide for the details.
Why does reheated fish smell so strong?
Healthline notes that microwaving fish can leave a fishy smell, and The Takeout says the smell can take over the kitchen and linger. Neither source explains why. It is a quality issue; wrapping the fish in a foil or parchment pouch locks the smell in, says The Takeout.
Is 125 to 130°F enough to reheat fish?
That is America's Test Kitchen's target for a moist result. It is well below the 75°C used for leftovers in the UK sources we read. For leftovers, reheat until steaming hot all the way through, or eat the fish cold within 2 days.
Related answers
Primary source: FSA/NHS reheating guidance.
General information only, not medical advice: see the medical disclaimer. Feeling unwell after eating something? Contact NHS 111 or your GP.