How long does raw marinated fish last in the refrigerator?
A suprisingly difficult question, and I won't be able to
conclude with a safe number either -- only a little science. The
major factors that come into play in marinating fish are: * What
kind of fish? Fat content is important. * Caught when and stored
how, before you got it? * Contents and particularly pH of marinade.
* The temp if your refrigerator. You want to keep the fish in a
marinade as close to 38-42F as you can. Above 42F we start seeing
microbial action (the 38F part is because your fridge is not always
the same temp unless you never ever open it). In the 60F range
we're into serious growth action -- except for.... pH. If the
marinade is highly acidic (ceviche with a lot of lime), you get
more leeway, as highly acidic environments aren't comfortable for
the usual bacterial culprits. Salt is another mode. Malayans
fermented fish with salt and buried the whole thing for months, and
then ate it. Some died. Most didn't. Salt acts as a dessicant, and
a teaspoon is all you need to flavor my rice and yours. Naturally,
salt and acid works even better. Fat -- the more the worse. Shrimp
are right around as bad as you can get. Only an hour or so at room
temp internally and it's almost certainly infected. Hallibut,
however, lasts a lot longer, as does Tilapia (which makes a
miserable but safe fish to marinate). Tuna sushi cut in America is
middle of the road. Toro (tuna belly) is fattier and more
dangerous. Caught and stored is the hardest. So the best you can do
it pcik it right at the fishmonger's. Nothing you buy should smell
fishy. It should smell clean, like the ocean. It should be firm and
not hold a fingerprint (deadly news) and it should respond from an
indentation made with your finger (if it doesn't bad news). Any
fish monger who won't let you smell, and touch with gloves on
(they'll have some) -- don't deal with them. Now -- given a decent
fish (not shellfish but maybe a halibut or tuna) and an acidic and
a little salty marinade (think ceviche for a baseline) and a dead
solid 40F fridge -- this might survive easily 3 days if covered.
Sooner is of course better. Over 5 days you're seriously rolling
the dice, even if all else is perfect.
