So let’s say you’ve got some fresh salmon
in the back of the fridge.
Or at least it was fresh a day or two ago
before you totally forgot about it.
Now you pull that pricey filet out, and get
a nasty whiff of super-fishy stink.
But don’t throw out that salmon!
We’ve got some quick tricks to un-stink
your fish.
First, here’s a recap of the chemistry behind
the stink.
The cells of many fish have loads of an odorless
chemical called trimethylamine oxide, or TMAO,
plus lots of free amino acids.
These amino acids give fish its sweet, savory
flavor.
But fish didn’t evolve extra-tasty cells
just to make your sushi delicious.
Their cells load up with these dissolved chemicals,
called solutes, to prevent osmosis.
Otherwise, fish cells shrivel up as water
moved from an area with few solutes—like
a cell’s insides—into an area with lots
of solutes, like the salty ocean.
Shriveled cells equals dead fish, well before
it ever gets big enough to eat.
When your salmon was first caught, it smelled
fresh and clean.
Then, the bacteria on it started breaking
down TMAO into TMA, that’s trimethylamine
[trimethylamine - highlight the amine part
of the word “Trimethylamine”].
But don’t take it from me, a video voiceover—take
it from chemist Steve Maguire.
“That distinct fishy aroma is an amine,
which is an organic molecule, and it can evaporate,
go up your nose, and make you smell fish.”
Amines [aye-means] are notoriously smelly
- if you’ve ever had a whiff of decaying
meat, that’s an amine.
So let’s get rid of that stink with chemistry.
Here are three tricks to make fish less fishy:
When a fish finally gets to your fridge, bacteria
on its surfaces have had a few days to churn
out smelly TMA.
We can’t tell you how to go back in time
to stop those bacteria, but we can tell you
this.
Rinse off that stinky coating of bacteria
and TMA by running cold tap water over your
fish.
Don’t use hot water, because it’ll cook
your fish a little and you won’t get the
same results when you whip up your best recipe.
Pat dry and cook—or try our next trick.
Soak your fish in milk for 20 minutes.
DRAIN, pat dry, and cook.
Seriously.
During the milk soak, a milk protein called
casein binds to TMA and extracts it from the
fish.
When you pour off the milk, you’re pouring
off that casein-bound TMA.
If you’re out of milk, don’t despair!
We have one more trick.
Cook your smelly fish in acidic liquid, or
dunk your cooked fish in acidic sauce.
But not because you want to punish it!
Remember that stinky TMA molecule?
Steve: “It is basic, and if you introduce
an acid to it, say lemon juice, or vinegar,
or tartare sauce, the acid and base react.”
Acids and bases reacting make new products,
something called an acid salt and water.
The acid salt stays dissolved in the water,
so the stink is contained.
And if you can’t smell it, you don’t taste
it either.
Thanks chemistry!
With these tricks, you can turn your stinky
fish into tasty delish, and stop throwing
out still-good salmon.
But chemistry can’t protect you from truly
rotten fish.
The FDA recommends eating refrigerated fish
within 48 hours, so don’t forget your Friday
fillets until Monday.
If you’re into 
knowing more about just how stinky amines
can get, check out this video about putrescine
and cadaverine.
Or if rotting meat isn’t your style check
out this video on how odor eliminators work.
