Cooking Tips · Ingredients

Is a lime just a green lemon?

Last week’s Cooking Tip was all about Lemons. They are not the only citrus fruit that has wonderful culinary uses. In this Cooking Tip, let’s look at Limes. Many of the points made about lemons are also true of limes as far as buying them, storing them and the importance of the zest along with the juice. I won’t repeat those in this Tip but, rather, discuss some of the differences.

Limes are the most acidic of all citrus fruits. As much as 8% of their weight comes from citric acid. They are much less sweet with more bitter notes than lemons. Just as with lemons, there are different varieties. The most common in supermarkets are the Persian or Tahitian lime although you will also see others.

I advised staying away from greenish lemons as they are probably underripe. This is not a good indicator for limes as their natural color is green. Also, limes are generally harvested while they are not completely ripe. Limes tend to turn yellowish-green when they are at their best. If buying a Persian lime, try to buy one that is lighter green with hints of yellowing. Feel the skin and opt for those with smooth skin. Just as with lemons, choose ones that seem heavy for their size and ones that give a bit upon pressing.

Persian limes (Bearss limes & Tahitian limes) are larger than other limes, oval in shape and less acidic. The Tahitian variety is even more oblong in shape. For culinary purposes, the Tahitian and Bearss can be used interchangeably. Some sources say they are less tart than Key limes and others claim they are tarter. You will have to do a taste test to decide for yourself. They are certainly the juiciest.

Key limes (sometimes called Mexican limes) are very small (1-2 inches in diameter) and round. They are sought out for dishes/cocktails due to the intense flavor. Due to their small size, you would have to squeeze about 40 of them to get one cup of juice. That compares to 6-8 Persian limes to obtain the same yield. The average medium lime (2½-3oz) will yield about 1½-2 tablespoons of juice.

For an interesting perspective on Key limes, see this article from Serious Eats. In summary, the author feels that Key limes are more of a “Key Lie” since we import them from Mexico and she feels they are not like the authentic version. She brings up the subject of “terroir”, a concept that is usually applied to grapes/wine. The terroir is everything that could affect the taste & quality of the item from soil to climate to harvesting techniques and so much more. Just as we are not allowed to call a sparkling white wine “Champagne” unless it is grown in that region of France, Mexican Key Limes are a misnomer.

She states the Key limes that were grown in the Florida Keys were “fat and juicy, with well-rounded acidity and a rather yellow rind; a point of pride for Florida growers.” Our Mexican key limes are tiny, dry and bitter. For more detail, see the article. Just as with lemons, the bottled key lime juice is nothing like the fresh. I have tried the one that our store carries, Nellie & Joe’s Key West Lime Juice, and, in my opinion, it was nothing short of terrible. Although I could not find documentation of this, the author of this article implies that it is made with imported Mexican limes although the company has “Key Lime” in its name. Have you tried it? If so, let me know what you thought.

There are also some more uncommon fruits in the lime category. The Kaffir lime looks distinctive with a very bumpy skin. They are small, very tart, very acidic with very little juice. Because of these characteristics, they are not really used for cooking. Rather the peel and leaves are what is used and are very common to Thai cooking.

Finger limes, native to Australia do not really look like a lime. They have bumpy skin and a cylindrical shape. They are sometimes called “caviar lime” due to the flesh that looks like small caviar pearls rather than the typical juice sacs. They have a very tangy and sour juice.

The Philippine lime is also known as calamansi, calamondin or musk lime. It is a very tart lime used in Philippine cooking. It is very small and orange in color. They do not travel well and so, will not be something you will normally find in the US.

Using limes is similar to using lemons. At times, you want that distinctive lime flavor. Limes also adds a characteristic tartness and flavor to salsas, southwestern and Asian dishes. Lime is commonly added to cocktails and other beverages. Also, just like with lemons, a dash as you finish your dish adds a wonderful brightness.