Oyster Sauce
Ingredients.
One dozen Oysters.
Half an ounce of Butter.
Half an ounce of Flour.
One tablespoonful of Cream.
The book gives quantities only; the method was assumed to be common knowledge in a professional kitchen of the period. What follows fills in the working details a modern cook needs.
- What the proportions describeHalf an ounce each of butter and flour is a small white roux, enough to thicken roughly half a pint of liquid (about 10 fl oz by British measure). The liquid was presumably the strained oyster liquor made up with fish stock or milk; the ingredient list omits it, which suggests the cook was expected to take the stock as given.
- WeightsHalf an ounce of butter is about 1 tablespoon; half an ounce of flour is a scant 2 tablespoons. One tablespoon of cream is genuinely all that is called for — this is a finishing enrichment, not a cream sauce.
- The hinge: cook the oysters barely at allPoach the shucked oysters in their own liquor only until the edges ruffle, well under two minutes, then lift them out and set them aside while the sauce is made. Oysters left in a simmering sauce turn firm and rubbery and give up their liquid, thinning the sauce as they go.
- Beards and gritPeriod sauces often had the tough beard trimmed away and the oysters cut in halves or quarters if large. Always strain the liquor through a fine sieve or muslin; a single fragment of shell will ruin the texture.
- A dozen oystersOyster size varies a great deal, and the size the recipe assumes is not stated. If your oysters are large, six to eight cut up will sit better against this quantity of sauce than a dozen whole.
- Do not boil after the cream goes inAdd the tablespoon of cream and the reserved oysters off the heat, or at the barest simmer. Seasoning is traditionally salt, cayenne and a squeeze of lemon; the oyster liquor is already salty, so season last.
- YieldAbout half a pint of sauce, enough for four servings alongside poached or boiled fish, or for a boiled fowl.
Oyster sauce in the British sense has nothing to do with the fermented Cantonese condiment of the same name; it is a plain white sauce built on oyster liquor, and through the eighteenth and nineteenth centuries it was the standard accompaniment to boiled cod, turbot and boiled fowl. Oysters were cheap and abundant in Britain until the beds were badly overfished late in the nineteenth century, which is why cookbooks of this period treat a dozen of them as an unremarkable seasoning rather than a luxury.