Ann Reardon

Rock Candy Geodes Recipe

how to make rock candy

Geodes are beautiful so let’s make them delicious too. Follow the step by step instructions to make fondant or chocolate rock candy geodes. You can give them as a gift on their own or use them in cake decorating.

Fondant shell
350g (12.35 ounces) fondant
black and brown coloring

Using aluminum foil make a bowl into a rock shape and line with another sheet of aluminium foil.
Marble some grey, black and brown shades of fondant as shown in the video and roll it out.
Roll out some white fondant and place over the top of the coloured fondant.
Place the fondant (rock colour down) over the aluminium foil bowl. You can leave this to dry out or use immediately.

Supersaturated sugar solution recipe

3 cups or 640g (22.58 ounces) sugar
1 cup or 230ml water
few drops of food coloring
few drops flavoring

Heat the sugar and water in the saucepan and stir until completely dissolved. Remove from the heat.
Allow supersaturated sugar solution to cool slightly and then pour into the fondant shell. Leave overnight for crystals to form.
Remove any excess crystals that have formed in the middle, turn upside down and leave to dry out.
Using a sharp knife, trim off excess fondant around the level of the sugar crystals.

Chocolate Shell

how to make rock candy

300g (10.58 ounces) white chocolate melts or candy melts
2 Tbsp or 14g (0.49 ounces) cocoa powder

Make an alfoil bowl as shown in the video and pour in the hot sugar solution, completely wrap in alfoil and leave for 48 hours for crystals to form. Tip off excess sugar solution, peel off alfoil and leave upside down to drain.
Melt some candy melts or white chocoalte melts and pour over the back of the candy shell. Once set add some cocoa powder to the remaining melts and pour over the top of the white chocolate. Trim to the edges of the crystals.

rock candy recipe

by Ann Reardon How To Cook That

My Cookbook

ann reardon crazy sweet creations cookbook
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All recipe quantities in the book are in grams, ounces and cups.

182 Comments View Comments

  1. 1terminal

  2. Rating: 1.5

    Did not work at all. Made a 1/4 size batch of sugar syrup, left it in its fondant shell for 24 hours and pretty much nothing had happened. Left it a total of 5 days and had some very grainy crystal right in the bottom, but also the fondant was completely soft and was weeping, the sugar syrup had seeped through in places. It all went in the bin. Waste of time and effort, and it was such a shame!

    • Sugar solution even, not sugar syrup.

      • Also it’s late at night here and I’ve just realised how harsh this comment is and I apologise. I was frustrated with it not working!

        • Rating: 5

          Just read your comments and wanted to congratulate for apologizing and explaining. I am just a reader and so understand. My rating is for you….

  3. Rating: 4.5

    Can I use marshmallow fondant?

  4. […] candy geodes a little earlier on our list, but they were small and quick. Here’s a tutorial from How to Cook That that shows you how to make a shockingly authentic full sized version of an actual edible […]

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