Trout, sea trout & grayling

Nick Fisher

LATIN NAME

Brown trout and sea trout: Salmo trutta. Rainbow trout: Oncorhynchus mykiss. Grayling: Thymallus thymallus

SEASONALITY

Farmed trout: not applicable. Wild trout, sea trout and grayling: closed seasons are determined by local byelaws

HABITAT

Largely farmed; some healthy stocks of wild brown trout in Scotland and Ireland; sea trout can be found in freshwater rivers and coastal waters across the British Isles

MCS RATING

Farmed trout 1–3

REC MINIMUM SIZE

Wild brown trout 25cm; wild sea trout 40cm; grayling 30cm (but in all cases, check local byelaws)

MORE RECIPES

Potted carp; Dab in a bag; Fried salmon with cucumber and gooseberry salad; Fried fillets of perch with sorrel and new potatoes; Steamed sea bass with kale and ginger; Rice and fish with wasabi dressing; Cucumber, smoked mackerel and dill salad

SOURCING

graigfarm.co.uk; streamfarm.co.uk; thefishsociety.co.uk

In taxonomic terms, trout, sea trout and grayling are members of the Salmonid family. They share with the salmon tribe an adipose fin (a nubby little thing between dorsal fin and tail), and a propensity to sometimes migrate to salt water. I say sometimes, because it’s complicated. Grayling don’t migrate and trout do, but only some trout and only when it suits them.

There are many different kinds of trout: brown, rainbow, blue, ferox, tiger and dollaghan, all of which can be fascinating if you’re an angler, but cooks need only concern themselves with brown and rainbow.

Brown trout is a native fish. Rainbow trout originates from America. Native brown trout range from tiny tarns in the high hills of Scotland and the Lake District to the chalk-stream rivers of Hampshire and Dorset. Rainbows don’t breed in Britain (apart from one or two small freak populations) because conditions don’t suit.

Both these fish are farmed in the British Isles. The trout you buy, in any form, will mostly be farmed rainbows because they do best in an aquaculture set-up. They’re aggressive, hungry feeders and in the right conditions will quickly pile on the pounds. But farmed brown trout occasionally turn up on fish slabs too. There’s not much to choose between them flavourwise. Both species are fed on the same fishmeal pellets, which means their flesh tends to be highly coloured and their flavour very salmony.

There are some excellent trout farms with lovely, clean water, which produce very fine fish – and organic farms that use carefully sourced fishmeal. But the flavour of a farmed trout will never be as good as that of a wild fish that has foraged its way through nature’s aquatic-insect buffet.

Many fish farms also grow trout for restocking rivers and lakes. When released, these are caught by anglers, who pay to take them home. These fish, once they have naturalised and started eating flies and the like, have paler flesh than their farmed relatives, with more of a natural, freshwater fish flavour.

Truly wild brown trout are delicious, especially the little ones taken from highland tarns and small rivers. But stocks are precarious and vary from region to region, so catch-and-release is mandatory in most well-managed rivers these days; i.e. the fish must be returned to the water alive. However, in some unpolluted, lightly fished Irish and Scottish lochs, large heads of wild brown trout still thrive. So my dream breakfast of wee wild brownies fried in butter with foraged mushrooms is, while a very rare treat, still just about possible.

Grayling are just as delicious as trout. They used to be considered vermin in chalk-stream rivers because of their assumed propensity to eat valuable trout eggs. However, those beliefs have evaporated in the last 20 years and now even the fanciest river fishery is proud to boast a healthy head of grayling. Hugh and I once fried a few on a riverbank with wild garlic leaves and salty butter – an exceptional wild meal.

The chances of finding grayling at the fishmonger are very slim because there is no fishery that targets them. Should you ever see one on the slab – or on a menu, or in a friendly angler’s creel – don’t even draw breath. Buy it and bake, steam, fry or grill it. The flesh is firm, creamy white, lovely with herbs, hot or cold, perhaps augmented with a lovingly hand-made mayonnaise.

On the rare occasion when I cook farmed trout, I’ll cook it whole, on the barbecue, with a bellyful of bay leaves and butter, or some chives and dill to pep up the flavour, wrapped in foil for the first 5–10 minutes then opened up to let the steam out for another 5 minutes or so.

Sea trout

Excellent as trout and grayling can be, sea trout is altogether superior. Delicately salty but firmly muscular, it tastes like a cross between a bass and a truly wild salmon. But a sea trout is actually just a brown trout – a spotty, cheeky, mini-banana-sized, river-born wild native brown trout that has decided to follow its salmon cousins’ macho migratory habits and take to the ocean. This is nature’s way of preserving the species. A brown trout that overwinters in an inhospitable winter river will probably die. Even if it lives, it won’t produce a heap of eggs because it is half-starved. However, if some of the brown trout are programmed to go out to sea (we still have no idea how this programming works), they will, if they survive the process, get big.

A sea trout doesn’t go across the Atlantic, like the Atlantic salmon. Mostly it just mooches around the coast, in and out of estuaries, feeding on crabs and worms and shrimps for a year or two, getting big and turning from brown to saltwater silver. Then, once it weighs anything up to 5kg, it’ll head back up a river to lay some beefy, fit, fertile eggs – of which it now carries millions.

Just to ensure the brown trout bloodline continues, there is perfect interbreeding capability. A huge, sleek, prawn-fed female sea trout can still mate with the tiny finger-long brown trout male who never left the home river in the first place. Sea trout are an enigmatic miracle of nature.

Some sea trout find their way into the retail fishmonger chains during the summer. Not surprisingly, shoppers are often confused by them and will plump for farmed salmon instead, which means that this life-changing fish is very reasonably priced. For my money, poached or steamed sea trout with fresh samphire and a lemony vinaigrette is pretty much heaven on a plate.

FOIL-BAKED TROUT WITH BABY BEETROOT AND SPRING ONIONS

Baking fish whole in foil is a great way to keep it moist and full of flavour. Trout are an ideal size for this treatment and their juices taste wonderful when mingled with beetroot, butter, wine and herbs. Perch are also excellent cooked this way. Serves 2

2 tbsp olive or rapeseed oil, plus extra to oil

10 cooked golf-ball-sized baby beetroot (see Roasted Beetroot Orzotto with Lavender), or 2–3 cooked larger beetroot

A small bunch of spring onions (about 8), trimmed and sliced

2 trout (325–375g each), gutted and descaled

2 garlic cloves, crushed

6 sprigs of thyme

6 sprigs of dill (optional)

2 bay leaves

1 lemon, sliced

40g butter

60ml dry white wine

Sea salt and black pepper

Preheat the oven to 200°C/Fan 180°C/Gas 6.

Put two double-layered pieces of foil, big enough to comfortably envelop each trout, shiny side down, on your work surface. Lightly oil the foil.

Quarter the baby beetroot (or slice, if using large ones), then arrange in the middle of each foil sheet to make a ‘bed’ for the fish. Scatter over the spring onions. If you have any nice, tender beetroot leaves left over, tear out the stalks, and add a few leaves to each parcel. Trickle 1 tbsp oil over the veg and add a pinch of salt.

Slash the fish flesh 3 times on each side, then season the fish inside and out. Stuff the cavity of each fish with the garlic, herbs and lemon. Lay the fish on top of the beetroot. Dot with the butter and add a few more drops of oil.

Bring up the foil around each fish to create a ‘bowl’ then trickle half the wine into each. Bring the foil right over the fish (but not tightly) and crimp the edges together so the fish are completely sealed in baggy foil parcels. Place on a baking tray.

Bake for 15–20 minutes, or until the trout is cooked through – the flesh nearest the head (the fattest part) should pull away from the bone easily. Place the foil parcels on warmed plates and take to the table, where they can be opened up. Serve with a green salad.