Maple Icing
1/2 cup milk 1 1/2 cup sugar 1 tablespoon butter 1 teaspoon vanilla 1/4 cup maple syrup Cook milk and sugar two minutes, add syrup and cook to soft ball stage. Remove from heat, add butter and vanilla. Cool and beat until creamy and thick enough to spread.
This is a boiled fondant-style icing: a sugar syrup cooked to the soft ball stage, then cooled and beaten until it turns opaque and spreadable. The temperature at which you beat it matters more than anything else in the method.
- Soft ball stageSoft ball is 234-240F (112-116C) on a candy thermometer; 238F is a reliable target for an icing meant to set firm but not crumble. Tested the old way, a drop into cold water should form a ball that flattens between the fingers.
- Cool before beatingThis is the hinge. Let the syrup drop to about 110F (43C) undisturbed before you start beating. Beat it hot and the sugar throws large crystals and the icing turns grainy; beat it cold and it seizes before it can be spread.
- Do not stir while boilingDo not stir more than necessary while boiling -- once the sugar has dissolved, leave the pan largely alone (the recipe does require adding the syrup after the first two minutes) and wash any crystals from the sides down with a wet pastry brush, since crystals on the pan sides can seed graininess in the finished icing.
- Maple syrupUse real maple syrup, not pancake syrup, which is corn syrup with flavouring and will not behave the same on the stove. Darker grades (now sold as Grade A Dark or Very Dark) give noticeably more maple character than the pale ones.
- Butter and vanilla off the heatAdd both after the pan comes off the burner, as the recipe directs. Vanilla is volatile and its flavour suffers if it is boiled, which is the usual reason for holding it back.
- If it stiffens too soonBeat in a teaspoon of hot milk or cream at a time until it loosens. If it stays runny, it was undercooked; returning it to the pan with a spoonful of water and reboiling to 238F will usually save it.
- YieldThe text as transcribed omits the milk and sugar quantities, so the amount this makes cannot be worked out from the recipe as printed. Spread it quickly, as it sets as it cools.
Boiled icings of this kind were long a staple of American cake decoration, and penuche and maple fudge frosting are among their descendants. The technique is candy-making rather than baking: it is the same syrup used for fondant, stopped at the soft ball stage and beaten to a fine crystal rather than poured out to set hard. Maple appears here because it was one of the few sweeteners a northern household could produce itself, and community and company cookbooks of the period lean on it heavily for icings, sauces and candies. Many of their entries assume a cook already knows the thread and ball tests and give no thermometer readings at all.