Home › The Principles of Cookery › Royal Sauce, for Fish
Royal Sauce, for Fish
Beat two raw yolks of eggs with two ounces of fresh butter. Add gradually a tea-spoonful of elder vinegar, a tea-spoonful of tarragon vinegar, a tea-spoonful of soy, a pinch of cayenne, and a very small quantity of nutmeg. Pour the mixture into an earthen jar; set this in a small saucepan of boiling water, and keep the contents of the jar boiling, stirring briskly all the time until the sauce begins to thicken and presents a rich smooth appearance; be exceedingly careful that it does not curdle, which it will quickly do if not taken from the fire as soon as it is smooth and thick. Time, about ten minutes. Probable cost, 6d. Sufficient for three or four persons.
A hollandaise in all but name, thickened over water and sharpened with two flavoured vinegars and a spoonful of bottled soy. Everything depends on heat control.
- The hinge: do not let the sauce boilThe hinge: the recipe says to keep the contents of the jar boiling, but in practice only the water in the saucepan should boil -- the sauce itself must not. Keep it moving and pull it off the heat the moment it coats the spoon thickly, at roughly 160-170F; much beyond about 180F the yolks scramble.
- Quantities in modern termsTwo ounces of butter is 4 tablespoons (half a stick). Two yolks to that much butter gives a soft, custardy sauce rather than a pourable one; the teaspoon measures of vinegar and soy are as written and are meant to be small.
- The earthen jarAny heatproof bowl or small stainless basin over simmering water does much the same job, though the original stands the jar in the water rather than over it. A stoneware jar held heat gently and evenly.
- Elder vinegarVinegar infused with elderflowers, once a standard larder item and now rare. Use a floral white wine vinegar, or steep dried elderflowers in white wine vinegar for a few days. Do not substitute anything made from elder stems, leaves or unripe berries, which are not edible.
- SoyIn Victorian cookery "soy" means bottled soy sauce, imported and thicker and saltier than most of today's brands. A teaspoon of dark soy or a scant teaspoon of Japanese shoyu is close enough; add no other salt until you have tasted.
- If it starts to grainLift the bowl off the water at once and whisk in a teaspoon of cold water or a small knob of cold butter. Caught early this pulls it back; once it has fully separated, start again with a fresh yolk and beat the split sauce into it drop by drop.
- Timing and yieldAbout ten minutes is realistic over gently simmering water. As stated it serves three or four -- roughly enough for four fillets of poached white fish or salmon. Make it just before serving; it will not reheat.
An egg-and-butter sauce of the same family as hollandaise and Béarnaise; the "royal" in the title appears to be a flourish for a rich sauce, though its origin is not documented. Victorian cookery books carry recipes for a range of flavoured vinegars -- tarragon, elder, cucumber, chilli -- and bottled "soy" had been imported into Britain since at least the eighteenth century. Cooking in an earthen jar standing in boiling water is a home-made bain-marie, although purpose-made bain-marie pans were also to be had by this date.