Thursday, July 2, 2009

Limes can be substituted for lemon, with few exceptions

Excerpts from a Miami Herald article by Kathleen Purvis

Lime and lemons can be used interchangeably in recipes. Besides a slightly different taste, there are few instances where it will matter. Limes are a bit more floral, even if the lemon juice is acting as a thickener, such as in a lemon curd or lemon pie, the lime juice should still have enough acidity to do the job.

One instance in which you cannot swap is when you are canning tomatoes in a boiling-water canner. Recipes for canning tomatoes call for commercial, not fresh, lemon juice because the percentage of acidity in fresh fruit can vary widely, from 2.5 percent to 4.5 percent. (It depends on how old the fruit is, the season when it was picked and even how rainy it was.)

You need a dependable level of acidity to make tomatoes safe for canning, so you should always use bottled lemon juice if the recipe calls for it. And you certainly shouldn't swap in lime juice.