Chocolate Fruit Sundae

This is a blending formula rather than a cooked recipe: four fountain syrups combined in fixed proportion to make a single sundae sauce. The proportions matter more than the technique.

• The measures are fluid ouncesThe measures are almost certainly fluid ounces -- Strawberry 10, vanilla 10, raspberry 8, chocolate 4 comes to 32 fl oz, exactly one quart of finished sauce. In cups that is 1 1/4 cups strawberry, 1 1/4 cups vanilla, 1 cup raspberry and 1/2 cup chocolate.
• What a ladle meantA fountain ladle of the period is usually reckoned at roughly an ounce, though sizes varied. On that basis a quart of this sauce would dress something like two to three dozen sundaes, which suggests it was mixed for a working counter rather than for a household.
• Fountain syrups are not modern ice cream toppingsThese were thin, intensely sweet flavouring syrups built on simple syrup, closer to a snow-cone syrup or a French sirop than to a thick bottled sundae sauce. Substituting four modern squeeze-bottle sauces gives something far heavier and much less fluid than intended.
• Vanilla syrup is the diluentVanilla syrup is the largest single component -- Ten ounces of it, nearly a third of the total, suggests it is there to soften and carry the fruit rather than to be tasted on its own.
• Chocolate is a seasoning hereChocolate is a small proportion here -- At 4 ounces in 32 the chocolate is an eighth of the mixture. Fountain chocolate syrup was cocoa-based, and a sweeter modern chocolate sauce may be lost against the fruit at that dilution.
• The simple syrup baseNineteenth and early twentieth century fountain simple syrup ran very heavy, commonly in the region of a pound of sugar to each pint of water. That density is what kept the syrups from fermenting on an open counter and what gives the sauce its clinging texture on cold ice cream.
• Keeping itMixed syrup is sugar-dense but not sterile. Bottle it, refrigerate it, and use it within a couple of weeks; discard at any sign of cloudiness, gas or a fermented smell.
• ServingPour over plain ice cream, as directed. The formula assumes an unelaborated base, since the sauce is already carrying three fruits and a chocolate.