As the grandson of a farmer, I’m sensitive to the issues surrounding food and the environment and I try to buy local and certified organic whenever I can. Still, the flavors of the world are important to me, so I commute and shop by bike and make my carbon footprint as small as possible so I can rationalize buying foods brought from afar. Which brings us to today’s topic: limes.
The two varieties usually sold at retail are Persian limes (which are cloned cultivars) and key limes (which are true limes). Although marketing executives would like you to think otherwise, it’s rare that a lime grown in the Florida Keys makes it north even as far as Miami. Most key limes sold in the United States come from Mexico.
Persian limes grow in Florida, but it’s a tiny crop, so imports from Mexico, Central America and Brazil supply most of what it takes to make our pies, marinades and margaritas.
Look for: Skin color, which depends mainly on the maturity at harvest, ranges from intensely dark green to lighter shades of green to almost yellow. The depth and hue of green dissipates with storage length (more than about 60 days) and conditions (high temperature and low humidity).
A nice lime has a bit of give and will be heavy for its size with smooth or lightly grained skin. It’s fine if the skin has spots that are lighter green or yellow, as is often the case with Persian varieties. Key limes frequently have a mottled appearance, and that’s OK, too.
The important thing is to avoid any limes that look wizened or raspy, since limes seem to wither rather than develop more overt symptoms of decay such as mold. Rot spots, if detectable, will first appear as a softening at either end of the fruit. Also look for hard spots or a thickened pebbly texture, both indicators of thick skin and less juice.
Key limes are small, nearly round and seldom larger than 1¼ inches in diameter. Most are sold in netted 1-pound packages, although you can sometimes find them in bulk. Figure about 20 limes to the pound, each lime giving about 1½ teaspoons of juice.
Persian types run much larger and sell by the piece or pound. Beyond about 2½ inches in diameter you’ll get a higher proportion of waste. An ideal Persian lime is about 2 ounces and should yield about 2½ tablespoons of juice.
When you have a choice between buying by weight or by count, I think buying by weight is almost always the fairer measure for consumers. I know grocers fear the sticker shock of, say, $3 per pound, and that to a shopper a lime might seem cheaper at 79 cents each, but bigger fruit is not always best. Look for quality, not size.
When: Persian limes are harvested year-round, but the bulk of the crop appears in the summer on into early fall. Key limes should be available through July. However, as with some other types of citrus, key limes frequently have an “off-bloom” crop, so it’s not unusual to see them at other times of the year, too.
To store: Hold limes in a plastic bag stored in the warmest part of the fridge (the top shelf of the door) around 40 to 45 degrees.
Basic preparation: To my taste, key limes are a bit more tart than Persian types, a difference that can be noticeable in drinks but less so in cooking. I think fresh juice is always best, so I don’t try to save leftovers. And I never use canned or concentrated juice, which tastes bitter.
Wash the skin with a soft brush under cool running water. If you’re sensitive to the oils in lime skin, rinse your hands after you finish any lime prep, and certainly before you touch your eyes or nose.
Lime waste can be composted. But I have also run it through a garbage disposal, which acts as a great deodorizer. However, some disposals may not be powerful enough for the job, so check your machine’s manual before trying this.