Cream Filling

A creamed butter-and-sugar spread thickened with beaten egg white, meant to be sandwiched between bread or cake layers. Note that nothing in it is ever cooked.

• The uncooked egg whiteThe white is beaten stiff and folded into a cold butter-sugar base, then spread and eaten without any heating step. Raw egg white carries a Salmonella risk that the recipe never addresses, and there is no sugar syrup poured in hot enough to bring it to a safe temperature. If you want an uncooked filling of this type, use a current recipe written for it.
• Why the sugar does not helpFive tablespoons of sugar against a whole batch is nowhere near the concentration that would make the mixture inhospitable to bacteria, and a spread of this kind is likely to sit at room temperature once assembled. This is not a boiled frosting or a cooked pastry cream despite the name.
• "1/2 egg white"Half a white is roughly 1 tablespoon, and the only practical way to get it is to beat one white lightly and measure. Such a small quantity is awkward to whip to a genuinely stiff foam, which may suggest the quantities were reduced from a larger original.
• Salt placementThe salt is listed third but added last, after the beaten white. Dry salt stirred into a stiff foam tends to slacken it; adding it with the white at the start of beating would be easier.
• YieldRoughly half a cup — enough for a few small sandwiches, or a thin layer between two cake rounds.
• Name"Cream filling" here means creamed butter, not dairy cream or a custard. Nothing in the ingredient list is a cream in the modern sense.