Indian Fish Fry

How do you tell whether fish is fresh?

Use your eyes, fingers and nose in that order. Clear domed eyes, bright red gills and firm flesh that springs back when pressed indicate fish worth buying; sunken cloudy eyes, brown gills and a dent that stays are the opposite. The decisive test is smell. Fresh fish smells faintly of seawater, and the sharp ammoniac note that develops as it spoils is unmistakable once you have met it. No marinade hides it, and no amount of frying makes such fish safe or pleasant. Buy it last on your errands, keep it cold on the way home, and cook it the same day.

Why should fish not be marinated for long?

Because the acid in lemon or tamarind starts to denature the surface proteins, which is the same chemistry that makes ceviche. Twenty to thirty minutes seasons the flesh and firms the outside. Two hours turns the surface pale and mushy, and it falls apart in the pan. This is the single most common reason a home fish fry disintegrates. Salt behaves similarly, drawing water out and leaving a wet surface that will not take a crust.

What makes the crust crisp?

A dry surface, a dry coating and undisturbed contact with hot oil. Semolina works better than plain flour because its coarse particles stay separate and crunch rather than turning to paste; the rice flour fills the gaps and helps it stick. The fish must be patted dry before the marinade and must not be dripping when it meets the rava. Once it is in the pan, leave it alone for a full four minutes, since moving fish early tears the crust off and leaves it in the oil.

How do you know the fish is cooked?

Flesh that was translucent turns opaque and flakes when you twist a fork in the thickest part. On the bone, the flesh should lift away cleanly. Fish is cooked through at a much lower internal temperature than chicken or mutton and the whole thing takes seven or eight minutes, so the far greater risk is overcooking it into dryness. If you are unsure, cut into the thickest section and look: opaque all the way to the bone is done.

Which fish suits a fry?

Firm-fleshed varieties that hold together. Seer fish, pomfret, mackerel, sardine and kingfish are the coastal standards, and small whole fish take a fry particularly well because the bones keep the flesh moist. Very delicate fillets such as basa collapse and are better baked. The oily ones, notably mackerel and sardine, are also the ones carrying meaningful long chain omega 3, which our note on omega 3 foods and capsules sets out properly.

Is fried fish still a heart-healthy choice?

Largely yes, with a caveat about the oil. The fish itself is lean protein and, in oily varieties, a source of fats that are difficult to get from plants. A thin rava crust shallow fried in a few tablespoons absorbs far less than a thick batter deep fried, which is where the distinction really lies. Reusing frying oil repeatedly is worth avoiding. Reading the evidence on fat and cardiovascular risk without overstating it is the substance of the cardiac nutrition course, and a gentler treatment of the same fish appears in our Kerala fish curry.

Can it be made ahead or reheated?

Not well. The crust softens within an hour and reheating dries the flesh out. Fry it as it is wanted, which is easy enough given the short cooking time. If you must, an oven at 180C for six or seven minutes restores some crispness where a microwave destroys the rest of it. Cooked fish left out should not sit more than two hours, and leftovers belong in the refrigerator and on the next day's plate rather than the day after that.