Key Lime Fudge

Featured in: Desserts to Satisfy Every Craving

Pour the cooked milk, sugar, and salt mix over marshmallows, white chocolate, plus lime zest and juice. Mix till it’s silky, pop in the fridge till it’s firm, and slice small squares—you’ll love the citrusy kick.

A woman in a kitchen with a stove and oven.
Updated on Fri, 06 Jun 2025 13:52:13 GMT
Piled-up creamy lime fudge slices, finished with lime zest and surrounded by cut limes for brightness. Pin it
Piled-up creamy lime fudge slices, finished with lime zest and surrounded by cut limes for brightness. | cookingkitchn.com

I took my go-to summer pie and totally flipped it into the best fudge ever. The zingy lime with all that smooth sweetness will have your taste buds doing a happy dance. When I show up at a get-together with this, folks just keep sneaking more pieces. Seriously, once you taste it, you'll want more!

Irresistible Reasons to Try This

That bright lime and sweet white chocolate combo is out of this world. Imagine if pie and fudge teamed up! Plus, it's way simpler to pull off than you'd think. My kids go nuts squeezing limes and everyone dives for the mixing spoon.

What to Grab

  • Pep Up: 2 teaspoons grated lime peel
  • Zing Juice: 1/4 cup squeezed key lime juice
  • Mini Fluffs: 2 cups tiny marshmallows
  • Pantry Grab: 2/3 cup unsweetened evaporated milk
  • White Choc: 1 1/2 cups white chocolate bits
  • Plain Old Sugar: 2 cups granulated sugar
  • Salt Kick: 1/4 teaspoon salt

Dreamy Steps to Follow

Dig In
Slice the cooled fudge into little squares and watch them vanish. Stash any leftovers in the fridge if nobody eats them all first.
Let It Set
After pouring in your mix, even out that top. Leave it on the counter awhile, then chill in the fridge so it firms up.
Mix Goodies In
Lift your pot off the heat and add the rest—lime, marshmallows, zest, chocolate. Stir until glossy and dreamy.
Warm It Up
In a pot, whisk together the milk, salt, and sugar. Stir as it heats. Let it bubble, then keep going for 8 minutes. Your arm might feel it, but it's so good!
Line It Up
First, grab some parchment and line your pan. Makes getting fudge out a breeze later!

Make It Yours

Out of key limes? Use regular limes, they're fine! A little green coloring jazzes it up, and smashing up graham crackers on top turns it into a pie bomb!

My Favorite Tricks

Zest is a must for the best flavor, don't skip it! Stir as it cooks so it stays smooth. And if you need a shortcut, that Nellie & Joe's bottled juice is a lifesaver!

Keep It Tasty

Tuck your fudge in a container in the fridge and it'll be good for weeks. Want to save some? Wrap up pieces and freeze them, with paper in between so they don't glue together!

Change It Up

Top it off with graham crumbs for those pie vibes. Want it tropical? Toss in coconut. Or melt a little white chocolate and swirl it on for extra wow!

Stuff to Grab First

You just need a decent-sized pot, a spatula, maybe a thermometer, plus an 8x8 pan and parchment. Trust me, parchment saves you!

Awesome for Every Occasion

Summer bashes, holidays, whenever—this fudge is always the star. I like gifting it in cute bundles because that sweet and tart mashup is everyone’s favorite!

Chunks of tangy lime fudge piled on parchment with fresh lime halves nearby. Pin it
Chunks of tangy lime fudge piled on parchment with fresh lime halves nearby. | cookingkitchn.com

Frequently Asked Questions

→ Can I use regular limes instead of key limes?

Totally, you can swap in regular limes. Maybe use a touch less juice since they’re usually milder than key limes.

→ Why use marshmallows in fudge?

They help your fudge stay creamy and smooth while stopping it from getting too grainy or crumbly.

→ Why line the pan with foil?

It makes pulling the fudge out so much easier! Grease it first so nothing sticks and you get nice, neat pieces.

→ Do I really need to stir constantly?

Always keep stirring, or you’ll risk burning it. This step is what makes the texture just right!

→ How do I know it's ready without a thermometer?

After letting it bubble 5-6 minutes, it’ll get a bit thick and look a tad darker—timing’s usually enough if you don’t have a thermometer.

Key Lime Fudge

Smooth white chocolate squares with a punch of key lime flavor in every piece. Sweet and tart tastes meet for an awesome treat.

Prep Time
15 Minutes
Cook Time
8 Minutes
Total Time
23 Minutes
By: Sophia

Category: Sweet Delights

Difficulty: Intermediate

Cuisine: American

Yield: 36 Servings (36 squares)

Dietary: Vegetarian, Gluten-Free

Ingredients

01 A small 5 oz can of low-fat evaporated milk.
02 One and two-thirds cups of regular sugar.
03 Half a teaspoon of salt.
04 12 big marshmallows, cut into quarters.
05 Two cups white chocolate pieces.
06 Grated peel from about five limes (1/4 cup).
07 Around two tablespoons of juice from key limes, roughly 5-7.

Instructions

Step 01

Put foil in an 8-inch square pan, then coat it with some butter.

Step 02

Mix together the evaporated milk, sugar, and salt in a sturdy pot. Heat it on medium until it starts bubbling.

Step 03

Turn the heat to medium-low and keep it boiling for 5 to 6 minutes. Don't stop stirring!

Step 04

Take it off the stove. Mix in marshmallows, chocolate, zest, and juice until smooth and melty.

Step 05

Pour the mix into your prepared pan and spread it out evenly. Let it cool down all the way.

Step 06

Cut the chilled treat into smaller, one-inch chunks.

Notes

  1. Normal limes can work fine if key limes aren't available.
  2. An 8-inch pan is a better choice than a 9-inch one.
  3. A double boiler isn't required but super handy.

Tools You'll Need

  • Thick-bottomed pot or a double boiler.
  • Square pan, 8-inch.

Allergy Information

Please check ingredients for potential allergens and consult a health professional if in doubt.
  • Contains dairy.

Nutrition Facts (Per Serving)

It is important to consider this information as approximate and not to use it as definitive health advice.
  • Calories: 100
  • Total Fat: 3 g
  • Total Carbohydrate: 17 g
  • Protein: ~