Key lime bars capture every ounce of key lime pie’s balanced, puckering sweetness—in miniature. 

Key Lime Bars Recipe: How to Make Key Lime Squares

Key lime bars are individually portioned desserts in the style of key lime pie, a classic American dessert with a creamy filling made from key lime juice, egg yolks, and sweetened condensed milk, served in a graham cracker pie crust. Like the [best key lime pie recipes](https://www.masterclass.com/articles/key-lime-pie-tips-techniques-and-fluffy-key-lime-pie-recipe), key lime bars allow for various toppings. 

Top the square bars with meringue, whipped cream, or, like a lemon bar, a simple coat of powdered sugar.   
Here’s how key limes differ from the regular limes that line the shelves of most grocery stores:

- __Color__: Ripe key limes have a yellow-green hue, while standard limes—also known as Persian limes—are deep green. 
- __Flavor__: Overall, key limes are more fragrant than other varieties, with lightly tart sweetness and less pronounced acidity. (Persian limes have a more bracing citrus flavor.) The mild tartness and floral scent of key limes make them ideal for desserts like [key lime cheesecake](https://www.masterclass.com/articles/key-lime-cheesecake). 
- __Origin__: Persian limes likely first arrived in the Mediterranean from Persia (modern-day Iran), and their popularity spread from there. In the summertime, key limes grow wild throughout the Florida Keys region of the United States. 
- __Size__: Key limes are smaller than Persian limes, with more seeds and a thinner, softer rind. 
Show up with key lime pie bars to your next potluck or party, and you’ll likely be the most popular person in the room. Here’s what to remember:

1. __Use fresh key lime juice__. Use fresh key limes for both juice and zest. If you can’t find key limes, use regular lime juice and zest, but avoid bottled lime juice and artificial lime flavoring. The acidity and delicate floral notes of fresh limes are unparalleled, and fresh lime zest infuses the filling with lime flavor. Here’s [how to juice a lime](https://www.masterclass.com/articles/how-to-juice-a-lime).
2. __Choose your crust__. Key lime bars consist of a lime curd filling atop a crumbly cookie base. For the base, choose between a classic [graham cracker crust](https://www.masterclass.com/articles/graham-cracker-crust-recipe) or a buttery [shortbread crust](https://www.masterclass.com/articles/shortbread-crust-recipe). If you like, add chopped pecans or pistachios for extra texture. Whichever you choose, make sure the baked crust has cooled before assembling the bars. 
3. __Chill the pie completely before slicing it into bars__. To preserve each bar’s neat layers, chill the filling until it’s completely set. If you’re making the pie in advance, place the entire pan in the refrigerator—with a sheet of plastic wrap gently pressed onto the surface—the night before serving. 
Key lime bars capture every ounce of key lime pie’s balanced, puckering sweetness—in miniature. 

Key lime bars are individually portioned desserts in the style of key lime pie, a classic American dessert with a creamy filling made from key lime juice, egg yolks, and sweetened condensed milk, served in a graham cracker pie crust. Like the <a href='https://www.masterclass.com/articles/key-lime-pie-tips-techniques-and-fluffy-key-lime-pie-recipe' target='_self' class='mc-text--link' data-mc-segment-trigger='true' data-mc-segment-event-type='Article Page Click' data-event-obj='{"textTag":"p","href":"https://www.masterclass.com/articles/key-lime-pie-tips-techniques-and-fluffy-key-lime-pie-recipe","linkCopy":"best key lime pie recipes","category":null}'>best key lime pie recipes</a>, key lime bars allow for various toppings. Top the square bars with meringue, whipped cream, or, like a lemon bar, a simple coat of powdered sugar.

What Are Key Lime Bars?

Here’s how key limes differ from the regular limes that line the shelves of most grocery stores:<ul class="mc-m-4"><li class="mc-my-4"> 1. Color: Ripe key limes have a yellow-green hue, while standard limes—also known as Persian limes—are deep green. </li><li class="mc-my-4"> 2. Flavor: Overall, key limes are more fragrant than other varieties, with lightly tart sweetness and less pronounced acidity. (Persian limes have a more bracing citrus flavor.) The mild tartness and floral scent of key limes make them ideal for desserts like <a href='https://www.masterclass.com/articles/key-lime-cheesecake' target='_self' class='mc-text--link' data-mc-segment-trigger='true' data-mc-segment-event-type='Article Page Click' data-event-obj='{"textTag":"p","href":"https://www.masterclass.com/articles/key-lime-cheesecake","linkCopy":"key lime cheesecake","category":null}'>key lime cheesecake</a>. </li><li class="mc-my-4"> 3. Origin: Persian limes likely first arrived in the Mediterranean from Persia (modern-day Iran), and their popularity spread from there. In the summertime, key limes grow wild throughout the Florida Keys region of the United States. </li><li class="mc-my-4"> 4. Size: Key limes are smaller than Persian limes, with more seeds and a thinner, softer rind. </li></ul>

Key Limes vs. Limes: What Are the Differences?

Show up with key lime pie bars to your next potluck or party, and you’ll likely be the most popular person in the room. Here’s what to remember:<ol class="mc-m-4"><li class="mc-my-4"> 1. Use fresh key lime juice. Use fresh key limes for both juice and zest. If you can’t find key limes, use regular lime juice and zest, but avoid bottled lime juice and artificial lime flavoring. The acidity and delicate floral notes of fresh limes are unparalleled, and fresh lime zest infuses the filling with lime flavor. Here’s <a href='https://www.masterclass.com/articles/how-to-juice-a-lime' target='_self' class='mc-text--link' data-mc-segment-trigger='true' data-mc-segment-event-type='Article Page Click' data-event-obj='{"textTag":"p","href":"https://www.masterclass.com/articles/how-to-juice-a-lime","linkCopy":"how to juice a lime","category":null}'>how to juice a lime</a>. </li><li class="mc-my-4"> 2. Choose your crust. Key lime bars consist of a lime curd filling atop a crumbly cookie base. For the base, choose between a classic <a href='https://www.masterclass.com/articles/graham-cracker-crust-recipe' target='_self' class='mc-text--link' data-mc-segment-trigger='true' data-mc-segment-event-type='Article Page Click' data-event-obj='{"textTag":"p","href":"https://www.masterclass.com/articles/graham-cracker-crust-recipe","linkCopy":"graham cracker crust","category":null}'>graham cracker crust</a> or a buttery <a href='https://www.masterclass.com/articles/shortbread-crust-recipe' target='_self' class='mc-text--link' data-mc-segment-trigger='true' data-mc-segment-event-type='Article Page Click' data-event-obj='{"textTag":"p","href":"https://www.masterclass.com/articles/shortbread-crust-recipe","linkCopy":"shortbread crust","category":null}'>shortbread crust</a>. If you like, add chopped pecans or pistachios for extra texture. Whichever you choose, make sure the baked crust has cooled before assembling the bars. </li><li class="mc-my-4"> 3. Chill the pie completely before slicing it into bars. To preserve each bar’s neat layers, chill the filling until it’s completely set. If you’re making the pie in advance, place the entire pan in the refrigerator—with a sheet of plastic wrap gently pressed onto the surface—the night before serving. </li></ol>

3 Tips for Making Key Lime Bars

Easy Key Lime Bars Recipe

Key lime bars capture every ounce of key lime pie’s balanced, puckering sweetness—in miniature.

Key lime bars capture every ounce of key lime pie’s balanced, puckering sweetness—in miniature. 
