Mint Syrup
Put a handful of mint leaves in a bowl and sprinkle with two tablespoonfuls of sugar. Bruise well and add one half pint of water to dissolve the sugar. Strain through cheesecloth, and add one pint strained honey, two teaspoonfuls of extract of vanilla, and two quarts of plain syrup. Bottle for use. This may be made into a delicious milk shake by putting two tablespoonfuls of the syrup in a glass, and adding enough milk to fill the glass, and an egg may be added to make an egg shake.
A soda-fountain formula rather than a kitchen recipe: it assumes you already have a stock of plain syrup on hand and are building a flavoured syrup from it. A few of its terms need translating.
- Plain syrupFountain shorthand for simple syrup, made in the trade at roughly two parts granulated sugar to one part water by weight, boiled briefly and skimmed. That is considerably heavier than the 1:1 syrup most bar books use now, and it is what makes the finished bottle keep and pour thick.
- YieldTwo quarts of plain syrup plus a pint of honey and half a pint of mint water gives just under three quarts, about 88 fluid ounces. At two tablespoons a glass, that is close to ninety servings, so scale down by a quarter or a fifth unless you are stocking a counter.
- A handful of mintRead it as roughly a cup of loosely packed leaves. Spearmint is the usual choice for a syrup like this; peppermint will read as candy.
- Why nothing is heatedThe mint is bruised with sugar and steeped in cold water, never boiled. Heat drives off the volatile oils and can turn the infusion grassy and dull in colour; whether the cold method here was a deliberate choice or simply the quickest way to work, the recipe does not say.
- Bruise, do not pulverisePress the leaves against the bowl with a muddler or the back of a spoon until they smell strongly of mint. Grinding them to a paste is generally held to give a bitter, grassy edge that the honey will not cover.
- StrainingCheesecloth doubled will catch leaf, but the syrup will still throw a fine sediment after a day or two. A coffee filter or a second pass through a fine sieve gives a bottle that stays clear.
- KeepingSugar concentration is the only preservative here, and the added mint water dilutes it. Refrigerate the bottle and use it within a month; watch for cloudiness or a fermented smell, which means it has picked up wild yeast.
- The egg shakeThe final suggestion has a raw egg beaten into cold milk and served at once. That was standard fountain practice, but it carries a real Salmonella risk today. If you want the texture, use a pasteurised egg or pasteurised liquid egg product, and skip it entirely for children, the elderly, pregnant women and anyone immunocompromised.
To be "on the water wagon" was slang for having sworn off drink, first attested in print around 1901. The American fountain grew up alongside the temperance movement and then boomed under Prohibition, when drugstore counters inherited a good deal of the saloon's custom, and the formularies that served them read exactly like this: a base of plain syrup, a flavouring, and a note on how to work it into a shake, a phosphate or a soda. Mint was a fountain staple partly because it was cheap and grew everywhere. The honey and vanilla here are doing what fountain flavourists always did, rounding a thin herbal infusion into something with body enough to stand up to milk.