Persian Limes differ from Key Limes (or “Mexican Limes”) in that they are larger, have thicker, darker green skins, and have very few seeds. They are about the size of a lemon.
Producers like these Limes because the trees are more cold weather tolerant, the fruit is easier to pick because the tree is thornless, and the Limes store better than Key Limes because the skin is thicker.
Unfortunately, though their Lime flavour is nice, it’s not as concentrated and nice as that from Key Limes.
In North America, Persian Limes are grown in Florida. A variety called Bearss, which is seedless and slightly larger, is grown in California.
Cooking Tips
Owing to the weaker flavour in Persian Limes, you’ll see many recipes specifying the use of Key Limes.
Substitutes
When swapping in Persian Limes for Key Limes, use a bit more Lime juice to compensate for the weaker flavour, and cut back accordingly on other liquid.
Equivalents
1 medium-sized Persian Lime = 2 tablespoons of juice and 1 ½ teaspoons of grated peel
6 to 8 medium-sized Persian Limes = 1 pound = 450g
History Notes
Possibly a hybrid between Mexican Lime and citron. Likely introduced into Mediterranean by way of Iran (Persia), from there by Portuguese settlers to Brazil, from there to Australia by 1824. From Australia to Tahiti, and from Tahiti to California sometime between 1850 and 1880. Introduced into Florida from California in 1883.
Literature & Lore
“The ‘limeade’ trees are heavy with the glossy green harvest. Picking of the Persians begins in the lime groves of Florida, the fruit coming to eastern markets between now and September.
The green Persian is as generous of juice as the golden lemon, yet it took a war to bring it to commercial importance. As lime import sources were cut, Florida took over to put this lime’s bracing goodness into the menu.
This is the fourth summer the big seedless greens have been seen in northern markets. Now they are an everyday find at the corner grocer’s, not merely a luxury for hotel service or to add that glamour touch to a bon voyage basket. Green as a jealous eye, but utterly ripe and juice-dripping. They have to be juicy—it’s the law of their state. More than two years ago Florida’s legislature passed bills requiring that limes fulfill the same rigid maturity rulings and juice tests which have long been applied to Florida oranges and grapefruit. Inspectors examine the fruit before it’s shipped, and only the best are given the nod of approval. A few Florida Key limes are around, but these are mere midgets and of no great importance. Now Florida growers are tearing out “Key” groves to replant with the ‘greens.'” — Paddleford, Clementine (1898 – 1967). Food Flashes Column. Gourmet Magazine. July 1945.