Home › Cake Fillings And Frostings › Brown Frosting
Brown Frosting
Make same as Boiled Frosting, using brown sugar in place of white sugar.
A one-line variant that depends entirely on the parent recipe: Fannie Farmer's Boiled Frosting is a sugar syrup beaten into stiff egg whites, roughly 1 cup sugar to 1/3 cup boiling water and the whites of two eggs. Swapping in brown sugar changes how the syrup behaves, so a few specifics matter.
- The hinge: cook the syrup by temperatureThe hinge: cook the syrup by temperature. Farmer's boiled frosting is cooked until the syrup threads from the spoon; on a thermometer that is somewhere in the 230-240F range, and most modern versions of this frosting are taken to roughly 238-240F. Brown sugar syrup is dark and opaque, so the visual thread test is much harder to read than with white sugar; use the thermometer.
- Pour hot, beat steadyAdd the syrup to the stiffly beaten whites in a thin stream while beating continuously, and keep beating until the frosting holds its shape and cools to just warm. Dumping it in at once cooks the whites into strings.
- Which brown sugarBrown sugar of the period was sold in grades and often carried more molasses than today's light brown. Light brown gives a mild caramel frosting; dark brown gives a much stronger, almost butterscotch flavor. Pack it firmly when measuring.
- Brown sugar is slightly acidicThe molasses in it helps prevent crystallization, so this version is a little more forgiving than white boiled frosting. It also foams more in the pan, so use a saucepan with more headroom than you think you need.
- Do not stir the boiling syrupStir only until the sugar dissolves, then leave it alone and wash any crystals down the sides of the pan with a wet brush. Agitation after that invites a grainy frosting.
- HumidityBoiled frostings sulk in damp weather and may never firm up. On a humid day cook the syrup two degrees higher, or choose a buttercream instead.
- Working timeIt sets fast once it reaches spreading consistency. Have the cake cooled, level and ready, and swirl it on quickly rather than trying to smooth it twice.
- YieldA batch of this size will cover a modest layer cake or a batch of cupcakes; judge against your own pan sizes rather than a fixed figure.
Boiled frosting was a standard American cake finish for decades, and the Boston Cooking-School Cook Book treats it as a base technique with a run of one-line variants hung off it. It is the same principle as Italian meringue, though Farmer never uses that name. The brown-sugar version reflects a kitchen where sugar came in grades rather than brands: refined white was the expensive default, while brown sugar, still holding some of its molasses, was cheaper and carried a flavor of its own. Later cookbooks would rename much the same mixture seafoam or sea foam frosting, and pair it with spice and nut cakes where its caramel note belonged.