Why Does My Frozen Fish Smell... Fishy?

July 20, 2013 1:35 PM

Salmon was on sale at the store, so I bought 3 lbs, cut it up into approx 0.5lb pieces, and froze each piece in a ziploc bag for later use. A week later, the same thing happened with cod. And then, at some point (days - 1 week), my freezer began to smell of fish. Then my fridge too. And finally my kitchen. Where did I go wrong?

Additional notes:
I can't determine if it was the salmon or the cod or both.
I know fish smells - I did not know that frozen fish does.
Yes - I tried putting bicarbonate of soda in the freezer: no difference.

I've eaten most of the fish now - there's only one salmon and one cod piece left - and the smell has died down.

The next time I buy fish for freezing, what should I do differently?

posted by forallmankind to Food & Drink (8 answers total)

Regular freezers go through a periodic freeze-thaw cycle in order to remain "frost free." This is why they are not good for long term storage of meat, fish and the like. Also, regular ziplock bags aren't the greatest for freezer storage.
posted by slkinsey at 1:41 PM on July 20, 2013 [3 favorites]

Did you get fishyness on the outside of the bags? Did you wash it off (the fishyness comes from fats)? If not, try wiping them down with something soapy and then rinsing them in cold water. Then put all the smaller bags in a bigger ziplock bag in the freezer.

Check the temperature of your freezer compartment too. Also, I'd place them towards the back so they don't warm up as much when you open the fridge.
posted by Good Brain at 2:03 PM on July 20, 2013

Wrapped in cold packs in the freezer, inside layers of plastic, in the back. The cold packs mitigate the thaw cycle effects.
posted by spitbull at 2:13 PM on July 20, 2013

Air and defrost cycles are the enemy of frozen fish. What you want to do next time is:
a) remove as much air as you can from your ziploc's (and use the freezer bags, not regular ziplocs)
b) after the fish is frozen, put a little water in the bag and swish it around to coat the frozen fish. Again remove as much air as you can.
c) repeat this again the next day

What you want to do is glaze the entire surface of the fish with a thin coat of ice. You can also freeze the fish on trays and dip them in water as an alternate method, but that takes more room. This will not only trap all odors within the ice bubble, but also prevent freezer burn.
posted by Runes at 2:14 PM on July 20, 2013 [14 favorites]

Why were the fish cheap? At stores here, it's usually because they are close to last date of sale. You should only freeze fish that are caught the same day, or at latest the day before. This is why sometimes, frozen fish are better than fresh. They freeze them on the huge unsustainable fishing "boats". Fish-fat is the worst, so I imagine it's the salmon doing the damage. But the cod might be in an equally smelly state, when thawed.
posted by mumimor at 3:01 PM on July 20, 2013 [1 favorite]

I used to work at a place which sold fresh fish - when the new deliveries came in (every other day), we were allowed to take the 'old' fish home. As much as I like seafood, it was impossible to eat all the bounty, so my method to save it was as follows:

As soon as I get home, scrub up and get knife and freezer ziplocs ready, as well as a stack of clean tea towels.
Take a filet, and rinse well under cold water...immediately place on tea towel to dry, and put another atop it; press lightly to dry.
Move filet to cutting board, and cut in appropriate size pieces. Wash hands.
Open a bunch of the ziplocs while hands are clean. One at a time, rinse the cut pieces again and...
Place cut pieces into their(individual) ziploc, squoosh air out, and fold that ziploc over, then seal.
Put this ziploc into another one (same size or maybe a little larger), and squoosh air out again, then fold over and label.
This worked for me for years, with never a fishy smell, and never a weird bit in the freezer to wonder about.

Hope this is helpful :)
posted by PlantGoddess at 3:45 PM on July 20, 2013 [7 favorites]

Fish should never smell fishy - it means its bad. Is that simple. Only buy fresh fish and cook it that day. No fish is good frozen unless it is flash frozen right on the boat and vacuum sealed. Even then, salmon in particular gets fishy when frozen due to the water that it absorbs and I don't recommend ever eating frozen and defrosted salmon.
The seafood I think you can safely freeze is shrimp and scallops.
posted by privatechef at 6:13 AM on July 21, 2013

Rinsing fish over and over is not great for the delicate flesh and of it is then frozen it will have absorbed water which will then make it mushy and soft.
posted by privatechef at 6:24 AM on July 21, 2013 [1 favorite]