Key Lime Pie

A bright, creamy, and perfectly tangy dessert that captures the essence of sunshine in a slice. With a buttery graham cracker crust and a silky filling made from sweetened condensed milk, fresh key lime juice, and a hint of sour cream, this classic Southern pie is cool, refreshing, and impossibly smooth. Baked just long enough to set, it’s best served cold with a dollop of whipped cream and a sprig of lime.

Why You’ll Love This Recipe

This isn’t just pie—it’s summer on a plate. Unlike traditional custard pies that require eggs and long baking, this version uses a clever trick: sour cream + heat = a richer, silkier texture without curdling. The result? A velvety filling with bold citrus flavor and just the right balance of tart and sweet. And with only 5–8 minutes in the oven, it’s one of the easiest showstopper desserts you’ll ever make.

Perfect for:

Spring and summer gatherings

Holiday tables (especially Easter or 4th of July)

Make-ahead desserts

Wowing guests with minimal effort

🍈 "I brought this to a potluck," said one home cook. "It was gone in 20 minutes—and everyone asked for the recipe." 

Ingredients

For the Filling

3 cups (720g) sweetened condensed milk (1 large can is ~14 oz; use 2 cans)

¾ cup (180ml) fresh key lime juice (about 20–25 key limes, or substitute Persian lime juice if needed)

½ cup (120g) full-fat sour cream (adds creaminess and stabilizes the texture)

1 tbsp finely grated key lime zest (use a microplane for best results)

For the Crust & Garnish

1 prepared 9-inch graham cracker crust (store-bought or homemade)

Whipped cream or whipped topping (for serving)

Thin lime slices or lime wheels (for garnish)

Extra lime zest (optional, for color)

Step-by-Step Instructions

1. Preheat the Oven

Preheat oven to 350°F (175°C).

Place an empty baking sheet on the center rack—this helps distribute heat evenly and prevents cracking.

2. Make the Filling

In a large bowl:

Whisk together sweetened condensed milk, key lime juice, sour cream, and lime zest until completely smooth and uniformly blended (~1–2 minutes).

✅ No mixer needed —a hand whisk works perfectly. 

💡 Fun Fact: The acidity of the lime juice "cooks" the milk proteins, much like ceviche—this is what gives the pie its set texture. 

3. Pour Into Crust

Gently pour the filling into the prepared graham cracker crust.

Use a spatula to smooth the top.

4. Bake Just Until Set

Place the pie on the preheated baking sheet.

Bake 5–8 minutes, until:

Tiny bubbles form on the surface

Edges are slightly puffed

Center still jiggles slightly when nudged

✅ Do not overbake —the pie will firm up as it chills. 

5. Cool & Chill

Remove from oven and let cool completely on a wire rack (~1 hour).

Transfer to the refrigerator and chill for at least 1 hour, preferably 2–3 hours, until fully set and cold.

6. Serve & Impress

Top with whipped cream, arrange lime slices around the edge, and dust with extra lime zest.

Slice with a sharp knife dipped in hot water for clean cuts.

Serve chilled.

You Must Know

Use real key limes if possible —they’re more aromatic and tart than regular limes.

Fresh juice only —bottled lime juice lacks brightness and depth.

Full-fat sour cream matters —low-fat versions may separate during baking.

Chill thoroughly —warm slices fall apart.

Store covered —prevents odor absorption and drying out.

Storage Tips

Store in the refrigerator, loosely covered, for up to 4 days.

Not recommended for freezing —texture changes upon thawing.

Add whipped cream just before serving to prevent sogginess.

Ingredient Substitutions

Key lime juice

Regular lime juice or lemon juice

Slightly different flavor profile

Sweetened condensed milk

Homemade (milk + sugar simmered)

Not practical, but possible

Sour cream

Greek yogurt or mascarpone

Yogurt adds tang; mascarpone adds richness

Graham cracker crust

Digestive biscuit or shortbread crust

For different base flavors

Whipped cream

Coconut whipped cream

Dairy-free option

Serving Suggestions

Pair with iced tea, sparkling water with mint, or a crisp white wine.

Great for brunch, picnics, or after-dinner treats.

Double the batch for parties or gift one to a neighbor.

Cultural Context

Originating in the Florida Keys in the early 20th century, key lime pie is a true American classic. Born from simple pantry staples—condensed milk (before refrigeration), local limes, and graham crackers—it became a symbol of tropical ingenuity. Today, it’s celebrated nationwide, especially during spring and summer holidays. This version honors tradition while adding sour cream for extra silkiness and stability.

Pro Tips

Double the recipe? Yes—use two crusts or make mini pies in muffin tins.

Make ahead: Assemble and bake 1–2 days ahead. Chill until ready to serve.

Want more tartness? Add an extra tablespoon of lime juice.

Label your dish: People will ask for the recipe.

Say “ready?” before slicing —it’s part of the ritual.

Frequently Asked Questions

Q: Can I use bottled key lime juice?

A: Only in a pinch. Fresh juice tastes brighter and less bitter.

Q: Why did my pie crack?

A: Likely overbaked or cooled too quickly. Bake just until bubbly and cool slowly.

Q: Is this gluten-free?

A: Only if using a GF graham cracker crust. Always verify labels.

Q: Can I make it no-bake?

A: Yes! Skip baking and chill at least 4 hours—but baking sets it better and improves texture.

Q: Can I use egg whites in the filling?

A: Not needed—the sour cream and heat do the job safely.

Allergy Information

Contains: dairy (condensed milk, sour cream, whipped cream), wheat (in most graham cracker crusts).

Gluten-free option: Use certified GF crust.

Nut-free: This recipe is naturally nut-free.

Always check labels—especially on pre-made crusts and condensed milk.

Nutrition Facts (Per Slice – Approximate)

Based on 8 servings

Calories: 340

Fat: 14g

Saturated Fat: 8g

Carbohydrates: 50g

Fiber: 1g

Sugar: 38g

Protein: 6g

Sodium: 280mg

Note: Nutrition values are estimates and may vary based on brands and substitutions. Not intended as medical advice. 

Final Thought: This pie doesn’t shout. It sits quietly in the fridge, cool and green, waiting to surprise you. One bite—tart, creamy, perfectly sweet—and you’re reminded: sometimes the best things don’t need eggs, flour, or fuss. They just need lime, love, and someone who says, “Let’s make it special.”