No. 101

Royal Icing, and Royal Icing Flavored with Zests

Glace Royale et Glace Royale Parfumee aux Zestes.

Royal Icing.—Put into a vessel the whites of one or several eggs (those not too fresh are preferable), and add to them some icing sugar, sifted through a very fine sieve, sufficient to have the eggs and sugar combined; form into a running paste, add several drops, either of lemon juice or acetic acid, according to the quantity of icing. With a wooden spatula beat up slowly to begin, then continue the action more briskly, always turning it in such a way that the air may enter, which helps to make the icing lighter and firmer. Beat it until the spoon, being lifted from the icing, it stands on it upright, without falling off. This royal icing is excellent for decorating pieces, cakes, etc., but for flowers or decorations to be made entirely of royal icing, then after beating, add more icing sugar, but do not get it too hard. Royal icing can be made any color by using vegetable colors.

Royal Icing flavored with Zests.—Put into a basin, half a pound of sugar, add a few spoonfuls of sugar flavored either with orange or lemon zest, adding gradually sufficient white of egg to allow it to flow; this icing is used for covering cakes.

← No. 100 Cooked Cocoa Icing Elementary Methods No. 102 Icing with Syrup for Cakes Flavored with Van →

For the Modern Kitchen Do not make this as written.

Royal icing is still made much this way in professional kitchens, but Ranhofer's version rests on raw egg white — and on a preference for old eggs — which is where it parts company with current practice.

The raw egg whiteNothing in this formula is ever heated. The icing sets by drying, not by cooking, so any Salmonella present in the white is present in the finished decoration. Icing left to harden at room temperature for hours does not make it safer; drying is not pasteurisation.
"Those not too fresh are preferable"The preference is explicit, not careless: older whites are thinner and looser, which is the reason usually given for their use in a flowing icing, though Ranhofer does not say so. Either way, the recipe calls for the eggs least suited to raw consumption. A current royal icing recipe, built on pasteurised whites or meringue powder, should be used instead.
Decorations are eatenPiped flowers, borders and lettering are not scenery — people eat them, and the ones made "entirely of royal icing" carry the largest share of raw white per bite. This is not a case where the risky element cooks off elsewhere in the dish.
Icing sugarConfectioners' or powdered sugar. The very fine sieve is specified here, which suggests a less uniformly ground sugar than modern boxed powdered sugar, which contains cornstarch as an anti-caking agent and sifts easily, though it still lumps in humid weather.
Acetic acidHere it means dilute vinegar acid, offered interchangeably with lemon juice; acid whitens royal icing and loosens it so it flows. Cream of tartar serves a similar purpose in many later recipes.
"Vegetable colors"In Ranhofer's day colouring matter sold for confectionery ranged from plant extracts to synthetic dyes, and labelling was loose; some colourings then in use would not be permitted today. The phrase should not be read as a synonym for the modern natural food colourings sold under that name.
The spatula testBeating until the icing stands upright on the lifted spoon is the stiff-peak stage used for piping detail. The looser "flowing" consistency described in the zest version is flood icing, for covering a cake surface smoothly.
The zest versionHalf a pound of sugar is roughly 1¾ to 2 cups of icing sugar. The "sugar flavored with zest" is a prepared flavoured sugar -- granulated sugar rubbed with orange or lemon peel until it takes up the oil -- rather than loose zest stirred in.

A Little History

Royal icing's name is traditionally linked to its use on grand ceremonial cakes, and the connection to the hard white sugar coatings on eighteenth-century bride cakes is tradition rather than documented fact; the term itself became common in the nineteenth century. Charles Ranhofer, chef at Delmonico's in New York for some three decades, places it in The Epicurean's "Elementary Methods" -- the section of foundational preparations a cook was expected to have at hand. Royal icing set rock-hard and held piped lettering and lace-work, and it was used for set pieces carried to table at banquets and then admired more than eaten. The flavoured-zest version is thinner and poured: a plain glaze over a plain cake, given interest by sugar rubbed with citrus peel.