Frosting
1 egg white (unbeaten) 1 1/2 cups confectioner's sugar 1 teaspoon vanilla extract, or other flavoring Put egg white into shallow dish; add sugar gradually, beating with wire whip until of right consistency to spread; add vanilla and spread on top and sides of cake.
This is an uncooked egg-white icing: the white is never heated at any stage, and the finished frosting sits on the cake at room temperature until it is eaten.
- The egg white is never cookedNothing in the method brings the white above room temperature, and sugar alone does not pasteurise it. Salmonella can be present in the white as well as the yolk, and a shell-egg icing spread on a cake and left out for hours is a textbook vehicle for it.
- Who is most at riskFrosted cake is often served to small children, elderly relatives, pregnant women and anyone immunocompromised — the groups for whom a raw-egg product carries the most serious consequences.
- Why 1900 did not worryWhy the period did not worry -- The modern understanding of egg-borne Salmonella enteritidis in intact shell eggs is a much later development. The book's confidence reflects the state of knowledge at the time, not the safety of the practice.
- The substitution is not a fix we will supplyModern versions of this icing exist and rely on pasteurised whites, powdered egg white or meringue powder. If you want a plain uncooked white icing, use a current recipe written around one of those rather than adapting the lines above.
- On the terms usedConfectioner's sugar is the same product sold today as powdered or icing sugar; the "wire whip" is a wire whisk. "Right consistency to spread" leaves the exact ratio to the cook's judgement.
- CoverageOne white and 1 1/2 cups of sugar is a small quantity by modern standards: likely enough to glaze the top and sides of a single small layer rather than to fill and cover a two-layer cake.
Uncooked icings of this kind sat at the easy end of a spectrum that ran from plain water-and-sugar glaze up through boiled frosting, where hot syrup was beaten into the whites, and "seven-minute" frosting, beaten over hot water — both of which did, incidentally, heat them. This one is the cheap and quick option: no thermometer, no double boiler, no candy stage to judge. It depends on commercial confectioner's sugar, which became a widely available grocery staple over the course of the nineteenth century; once it was, a frosting could be assembled in a shallow dish in minutes instead of built from boiled syrup. Vanilla extract as the default flavouring, with "or other flavoring" left open, points the same way: bottled extracts were by then common pantry goods.