Nick Fisher
LATIN NAME
Native oyster: Ostrea edulis. Rock or Pacific oyster: Crassostrea gigas
SEASONALITY
Native oysters September–April
MCS RATING
Wild native oysters 5, so should not be eaten (except PDO oysters from the Fal estuary which are harvested sustainably). Farmed oysters 1
SOURCING
goodfishguide.org; faloyster.co.uk (for native wild oysters from the Fal); richardhawardsoysters.co.uk
Oysters are all about water quality. Suck and blow, suck and blow is all an oyster does, all day long. It can filter up to 10 litres of water an hour, from which it extracts its essential nutrients. The salinity of the water influences flavour and texture as well as determining speed of growth. An oyster from Whitstable will therefore taste different to an oyster grown in Milford Haven.
Our once abundant population of wild native oysters is now seriously depleted. Thankfully, cultivated oysters are a sustainable alternative. Oyster farming is wonderfully benign, because nothing is added to the natural environment except the oysters. The ‘spat’, or young oysters, often come from commercial hatcheries, or may be taken in a controlled way from designated wild areas and grown on in commercial beds.
Farmed rock oysters, also called Pacific, are the ones you’re most likely to find on sale or on a menu. They are distinct from the smaller native oysters which, though still cultivated, are more expensive and only good between September and April, outside their breeding season when their flesh may taste ‘milky’. Hence the often-quoted adage to only eat oysters when there’s an ‘r’ in the month.
Rock oysters were introduced because they could be farmed easily and eaten at any time of year – it was assumed they’d be unable to spawn in our chilly seas, so would never be out of condition. This proved to be incorrect – rocks do occasionally spawn in our waters, but it is still relatively unusual and can be managed (by keeping them in cooler areas), which is why cultivated rocks are available all year round.
Buy oysters from an oyster dealer or restaurateur who knows which farm, in which estuary, they came from. If they know neither, steer clear. A good oyster is a thing of poetic joy. A bad oyster – one that makes your stomach churn – is a disaster.
Shucking an oyster requires a special oyster knife and a certain knack. Protect your non-knife hand with a folded tea towel and secure the oyster either by gripping it in your hand, or by holding it down on a board. Start with the flatter half-shell uppermost so that the juices collect in the deeper, lower half. Insert the knife beside the ‘hinge’, then twist to lever the shell open. Keep your knife angled slightly upward so as not to damage the oyster. Then sever the muscle that holds the creature to its shell.
Eat oysters raw, as soon as they’re open, with lemon, diced shallots and Tabasco. Revel in their salty other-worldliness. Or, if you’re squeamish, barbecue them in their shells, curved side down, until they pop open, then scoop on to warm pasta with a generous squeeze of lemon and a dash of olive oil.
PAN-ROASTED OYSTERS WITH CELERIAC AND THYME
It’s unusual to cook oysters for this much time, but the results are delicious: the process brings out all their umami flavours. Serves 2
FOR THE CELERIAC
150g peeled celeriac
Juice of ½ lemon
A little extra virgin olive oil
Black pepper
FOR THE OYSTERS
1 tbsp olive oil
A knob of butter
24 large rock oysters, shucked
2 sprigs of thyme
Slice the celeriac very thinly, then cut the slices into thin matchsticks (or use a mandoline to do this). Put the celeriac in a bowl and dress it lightly with a squeeze of lemon juice, a little extra virgin olive oil and a twist of pepper. Scatter the celeriac over 2 warmed plates.
Place a large non-stick frying pan over a medium heat and add the olive oil and butter. When bubbling, add the oysters and their juices (they might spit a little) with the thyme. Turn the heat down to medium. Cook the oysters for 7–8 minutes on the first side then flip them and cook for the same time on the other side, until crisp and caramelised.
Arrange the oysters over the celeriac, then scrape up all the crisp, tasty, sticky bits from the pan and sprinkle over the oysters. Serve straight away.