This recipe comes from a 13th-century Andalusian cookbook. The original version (in translation by Charles Perry):

Take lemon, after peeling its outer skin, press it and take a ratl of juice, and add as much of sugar. Cook it until it takes the form of a syrup. Its advantages are for the heat of bile; it cuts the thirst and binds the bowels.

A quick online search shows a few different interpretations of a “ratl” as a unit of measurement, but regardless, this is about a 1:1 ratio of lemon juice to sugar. So, here’s my version:

2 c. lemon juice
2 c. sugar

Mix both in a saucepan and bring to a boil, stirring until the sugar is fully dissolved. Lower the heat to medium and simmer until the liquid cooks down to about half its original size, occasionally skimming off any foam on the surface.

Use a cold saucer (I stick it in the freezer while I’m cooking) and drizzle on a few drops. If it runs slowly, it’s time to take it off the heat. (This helps because the syrup will act really runny while it’s still hot.)

This should make about 2 cups. You can mix it with water or club soda for a tart drink, or as a more general mixer in cocktails or mocktails, or pour it on pancakes.

Add the lemon syrup and carrot syrup to ginger ale for a delicious mocktail! The sweetness of the carrot and the tartness of the lemon help to balance each other out.