By Brooke Gazer

North of the border, we assign a specific name to each of these tangy citrus fruits, but in Mexico they are all called limones (lee-MOH-ness), regardless of size, shape, or color.

There are several varieties of lemons, but in north America, the Eureka lemon is the most common. This bright yellow citrus fruit was propagated in California in the mid-nineteenth century. It is slightly oblong, with a pointed tip on one end. Lemons have a sour flavor, but are considered sweeter and less acidic than the citrus fruit we call limes. The “lemon” type of limón is occasionally sold in Mexico, but is more expensive than limes.

There are two common varieties of limes. Persian limes (Citrus latifolia) are shaped like lemons, with a slightly smaller nub on the end. The small round ones are key limes (Citrus aurantifolia). These are usually bright green, because it is easier to ship and store the hard unripe fruit. But when this tiny lime ripens, the skin turns yellow. It also becomes softer, juicer, sweeter, and less acidic. Mexicans tend to prefer them green, but if you have access to a tree, leave some to turn yellow – the ripe ones make the best lemonade.

In the sixteenth century, the Spaniards introduced this little citrus fruit from Malaysia into the USA and Mexico. It was a commercial crop in the Florida Keys, until a hurricane in the 1920’s decimated the trees. After that, growers substituted the larger, hardier, Persian variety. Key limes still grow in Florida, but most small round limes in your grocery store originated from Mexico.

Mexico exports over $500 million dollars’ worth of limes annually. In the 1990s, NAFTA played a huge role in this economic windfall, as 90% of limes imported into the USA are from Mexico. These little green juice balls are beginning to be labeled “Mexican Limes”, and, were it not for the famous pie, the designation “key lime” might disappear altogether.

Regardless of its huge export potential, Mexico maintains a good portion of their limes for domestic use. This country devours 1.9 million tons per year and is rated as the world’s third largest consumer of limes. This citrus fruit, which is as indispensable as chilies in Mexican kitchens, plays an integral role in Mexican cuisine. Locals use both kind of limes but show a slight preference for the smaller round variety in savory dishes. These are slightly more acidic, which would be essential in a dish like ceviche.

Persian limes are seedless and, as they are larger, you can use a regular citrus juicer to make lime juice. The tiny ones require a hand-held apparatus resembling a garlic press. Key limes have a thin leathery rind, but Persian lime peel is closer in texture to a lemon. This makes it easier to grate and due to its size, it yields more zest. This is an important feature for baking because the zest packs a lot of flavor. For either lemon or lime, half a teaspoon of zest is equal to about a tablespoon of juice.

This may seem like sacrilege, but for the reasons mentioned above, I use Persian Limes to make Key Lime Pie. I’m including my recipe in this issue, adapted for the Huatulco grocery scene, along with a couple of simple alternatives.

Brooke Gazer operates Agua Azul la villa, an ocean-view B&B in Huatulco: http://www.bbaguaazul.com.