Last Christmas, I decided to make Coal Candy (Black Fudge) for my brother-in-law who jokingly claimed he’d been on the “naughty list” all year. When I handed him a box tied with a ribbon that said “You earned it,” his face was priceless—until he bit into one and realized it was actually delicious white chocolate fudge disguised as coal. The joke went over so well that I ended up making three more batches for other family members who needed a playful reminder about their questionable holiday behavior. What makes this Coal Candy so perfect is how simple it is to pull off. You don’t need a candy thermometer or any fancy equipment—just white chocolate, sweetened condensed milk, butter, and black food coloring. The result is smooth, creamy fudge that looks convincingly like lumps of coal but tastes like heaven. It’s become my go-to gag gift for the holidays, and honestly, even people on the “nice list” ask for it now.
Why Coal Candy (Black Fudge) Works Every Time
The genius of this recipe is how forgiving it is. Traditional fudge requires precise temperature control and constant vigilance, but this version uses sweetened condensed milk as a shortcut, which means you don’t have to worry about hitting an exact temperature on a thermometer. The white chocolate provides a creamy, sweet base that’s neutral enough to take on the dramatic black color from the food gel. Low, gentle heat is the key here—you’re just melting everything together until it’s smooth, then adding enough black food coloring to turn it into convincing “coal.” The fudge sets firm in the fridge overnight and cuts into clean squares that look rough and rocky, just like actual coal. Sprinkle some black or silver sugar on top before it sets, and you’ve got a treat that’s equal parts funny and delicious.
Ingredients for Coal Candy
The ingredient list is refreshingly short. You’ll need one 14-ounce can of sweetened condensed milk, which acts as the binding agent and adds sweetness without requiring you to melt granulated sugar. Grab 24 ounces of white chocolate chips—using white chocolate instead of milk or dark gives you better control over the final color. You’ll also need 4 tablespoons of unsalted butter to add richness and help the fudge melt smoothly. A half teaspoon of fine sea salt balances out the sweetness, and 1 teaspoon of vanilla extract adds depth. The star of the show is about 2 teaspoons of black gel food coloring—the gel type works best because it’s concentrated and won’t thin out your fudge. Finally, have some black or silver edible sprinkles on hand if you want to add texture and make the “coal” look more authentic.
How to Make Coal Candy (Black Fudge)
Prepare Your Pan
Line an 8×8-inch baking dish with parchment paper, leaving some overhang on the sides so you can easily lift the fudge out later. If you don’t have parchment, aluminum foil works too—just make sure to grease it lightly so the fudge doesn’t stick.
Melt the Base
In a medium saucepan over low heat, combine the sweetened condensed milk, white chocolate chips, butter, and salt. Stir continuously with a wooden spoon or silicone spatula. This is where patience matters—low and slow is the mantra. High heat will scorch the chocolate or cause it to seize up and turn grainy. Keep stirring gently until everything melts together into a smooth, glossy mixture. This usually takes about 8 to 10 minutes, though it can take longer depending on your stove and altitude. The mixture will slowly melt, and you’ll know it’s ready when there are no lumps left and it flows smoothly off your spoon.
Add Color and Flavor
Once everything is melted, remove the pan from the heat. Stir in the vanilla extract first, then add about 2 teaspoons of black gel food coloring. Start conservatively—you can always add more, but you can’t take it away. Whisk vigorously until the color is fully incorporated and you have a deep, jet-black fudge. If it looks more gray than black, add another half teaspoon of coloring and whisk again. Different brands vary in intensity, so adjust as needed until you get that convincing coal look.
Set and Chill
Pour the black fudge into your prepared pan and spread it evenly with a spatula. If you’re using sprinkles, scatter them over the top now while the fudge is still warm and they’ll stick. Let the fudge cool at room temperature for about 30 minutes, then cover it and transfer it to the refrigerator. Chill for at least 8 hours, or overnight if possible. This long chill time is crucial—it allows the fudge to set properly so it cuts cleanly instead of crumbling or oozing.
Cut Into Squares
Once the fudge is completely firm, lift it out of the pan using the parchment overhang. Place it on a cutting board and use a sharp knife to cut it into 1-inch squares. For the cleanest cuts, warm your knife under hot water, dry it off, and slice. Wipe the knife clean between cuts. The irregular edges and rough texture will make each piece look like a chunk of coal.
Pro Tips
- Use low heat throughout—high heat ruins fudge by making it grainy or oily
- Gel food coloring is essential; liquid coloring won’t give you a deep black
- Chill overnight for the best texture and easiest cutting
- Warm your knife between cuts for clean, professional-looking squares
- Store in an airtight container in the fridge to prevent sweating
- Let fudge sit at room temperature for 10-15 minutes before serving for best flavor
Creative Variations
- Use milk or dark chocolate chips for a darker base that requires less food coloring
- Add a teaspoon of peppermint extract for a minty twist
- Mix in crushed Oreos before setting for a cookies-and-cream version
- Swap vanilla for almond extract for a different flavor profile
- Add mini chocolate chips to the mixture for extra texture
- Top with edible glitter instead of sprinkles for extra sparkle
Troubleshooting Issues
If your fudge turns out grainy or oily, you likely overheated it. Try rewarming it gently over low heat and whisking in a tablespoon of condensed milk or a small pat of butter to smooth it out. If the fudge won’t set after chilling overnight, it wasn’t cooked long enough to evaporate enough moisture. You can actually put it back in the pan with a splash of water, reheat it gently while stirring constantly, and cook it a bit longer before pouring it back into the pan. If the color looks streaky instead of uniform, you didn’t whisk the food coloring in thoroughly enough—next time, whisk more vigorously off the heat. Fudge that’s too soft usually just needs more time in the fridge, or you can add a few more tablespoons of white chocolate chips next time to firm it up.
Ingredient Substitutions
- Use dairy-free sweetened condensed milk and vegan white chocolate for a plant-based version
- Replace butter with coconut oil for a dairy-free option
- Use milk chocolate or dark chocolate instead of white if you prefer
- Swap vanilla extract for coffee extract for a mocha flavor
Storage and Serving
Store your Coal Candy (Black Fudge) in an airtight container in the refrigerator for up to two weeks. Let it sit at room temperature for about 15 minutes before serving so it softens slightly and the flavors come through better. You can also freeze this fudge for up to six months—wrap individual pieces tightly in plastic wrap, then store them in a freezer-safe container or bag. Thaw in the fridge overnight before serving. This makes a fantastic gag gift: pack the coal pieces in a small box or burlap bag with a tag that says “You’ve been naughty!” or “Merry Christmas from the Grinch.” It’s perfect for white elephant exchanges, stocking stuffers, or anyone with a good sense of humor about their holiday behavior.
Frequently Asked Questions
Why does my fudge sweat?
Fudge contains moisture, and extreme temperature changes cause condensation on the surface. Keep it refrigerated until just before serving to minimize sweating.
Can I use milk or dark chocolate?
Yes, but you’ll need less black food coloring since those chocolates start with a darker base. White chocolate gives you the most control over the final color.
Will black food coloring stain my mouth?
It can temporarily, similar to eating a black lollipop or any dark food coloring. The staining is temporary and washes away quickly.
Why didn’t my fudge set?
It wasn’t cooked long enough to evaporate sufficient moisture. You can return it to the pan with a little water and cook it longer over low heat, then chill again.
Can I make this without a thermometer?
Absolutely—that’s one of the best parts of this recipe. Just cook over low heat until everything melts smoothly, and you’re done. No temperature testing required.
How long does it need to chill?
At least 8 hours, but overnight is best. This gives it time to firm up properly so it cuts cleanly into squares.
Can I freeze this fudge?
Yes. Wrap pieces individually in plastic wrap and freeze for up to six months. Thaw in the fridge overnight. It may be slightly drier after thawing, but it’s still delicious.
Coal Candy (Black Fudge)
Ingredients
Method
- Line an 8×8-inch baking dish with parchment paper, leaving overhang on the sides for easy removal. Set aside.
- In a medium saucepan over low heat, combine sweetened condensed milk, white chocolate chips, butter, and salt. Stir continuously with a wooden spoon or silicone spatula.
- Continue stirring gently over low heat for 8-10 minutes until everything melts together into a smooth, glossy mixture with no lumps. Be patient—low heat prevents burning and graininess.
- Remove pan from heat. Stir in vanilla extract, then add 2 teaspoons black gel food coloring. Whisk vigorously until color is fully incorporated and fudge is jet-black. Add more coloring if needed for deeper color.
- Pour black fudge into prepared pan and spread evenly with spatula. Sprinkle with black or silver sprinkles if desired while fudge is still warm.
- Let cool at room temperature for 30 minutes, then cover and refrigerate for at least 8 hours or overnight until completely firm.
- Lift fudge out of pan using parchment overhang. Place on cutting board and cut into 1-inch squares using a sharp knife. Warm knife under hot water and dry between cuts for cleanest edges.
- Store in airtight container in refrigerator. Let sit at room temperature 10-15 minutes before serving.
