Key limes are one of those citrus fruits that are only sold in grocery stores during certain months. This is because they have thinner skin and don’t keep as long as other varieties. But, they also have a more intense flavor than Persian limes- the latter being the variety that’s available year-round in the supermarket. You can make this recipe with either variety and both will yield that slightly floral, tart flavor that limes are loved for. But, if you can find key limes then use those for a more intense flavor.
These little limes get their name from Florida keys, but originally they were known as Mexican limes. After a particularly harsh winter in 1894-95, they were planted to replace the damaged lemon trees. In the 1920s they were largely replaced by the hardier Persian limes and today key limes are quite the treat.