Realistic Chocolate Wood Log

Come the holiday season I often looked for a decent log mould that I could use to make cakes in. I couldn't find anything good looking enough so I made one. 4 actually.

There are two ways you can achieve this. You can either go the cheap one shot way by making a gelatin mould or invest a bit more on silicon for a long lasting reusable mold.

Gelatin molds tend to give a matte finish that looks really cool as wood alternative but since it's quite moist it will also make the fat of the chocolate crystallize in a way that leaves white grainy spots. It looks kinda cool but you won't see those in any decent chocolate workshop.

Here is how you can make a real wood looking chocolate shell to create your best cake in.

For the Gelatin way :

• Gelatin (a lot of it)
• Or agar if you want vegetarian molds (yeah no, that's not a thing)
• Sugar
• A container barely bigger than your log
• Some nails and wooden beams or sticks (small ones, 1.5x1.5cm or 1/2in think)

For the silicon way :

• Food grade silicon (2 part silicon).
• some release agent (or mold release). I used petroleum

For both projects :

• Wood log - You can use different log styles, I tried whole log and quarter logs, they both give different but amazing results
• Varnish

The first step is to chose the style you want go give to your cake. That would depend on the log you choose as a model. Try to chose a quite "even" log as branches or rough patches might prove more difficult to unmold.

Now you need to select the side of the wood you want to be showing. Since this is a cake it will have to rest on a side. This side will be where you create your cake from. It means that it needs to be wide enough to unmould the chocolate shell and the wood log once it's hard.

For the whole log, it means creating a flat surface that the cake will rest upon. For that I used a reciprocating saw but any saw would do. The best would be to have access to a jointer to create a perfectly flat surface but I don't have any.

Please be careful, those fingers of yours might still prove useful.

You need to thoroughly wash the wood. Brush it and make sure that no loose bit might come off afterwards or that there are bugs or saw dust in the cracks.

With the quarter log I had to use a torch to burn some wood fibers that would stick out. Again, you want to have a rather smooth surface.Let it dry before applying a few coats of varnish. you can use shellac or oils, those would be food grade, but I went with classic Polyurethane varnish because it's faster and you won't bite into the (real) wood anyway.

The goal of this vanish coat is to seal the wood, preventing gelatin or silicon to bond with the wood.

When making a gelatin mold, you will use a container that will hold the gelatin while it sets with your log just beneath the surface. To be able to do so, you log will have to rest at the surface of your container and the gelatin will need to fill all your container space.

Once you have a flat surface on your log, you will nail some wood sticks to it and set it upside down in your container.

I'm sorry I don't have a picture of this step, so I created these award winning pictures instead. Photoshop king here, I know.

The first step is to determine how much gelatin you need to use.

For that you need to know the amount of water that will be used inside de container. The best way to do so is to put your nailed log into its container with the wooden beams resting across the top of the container.

• Fill the container with water, making sure that the log doesn't float on top. You can put some weight on it to keep it submerged. Be creative here ;)
• You can now remove the log and weigh the water. That would give you the volume of gelatin that you need to fill the container with.
• To know how much dry gelatin you need to use, we could go into details on what kind of gelatin and whatnot but you can count on a a small recipe to give you a strong gel.
• Divide the weight of water by 2 that will give you the weight of water that you need to boil.
• Once boiling remove from the stove and add the same amount of sugar. stir to dissolve
• Add half of this weight in gelatin. That's a lot. Bloom it beforehand in cold water and stir to dissolve.
• If need be, you can reheat the pan but don't boil it.

If you're really bad at maths, it means that If you measured one kilogram of water, that would mean 500g of water, 500g of sugar and 250g gelatin (125 standard 2g gelatin sheets - buy it by the kilo). If you use imperial, I'll let you do the math.

If the gel is too soft it won't hold. If it's too strong it will break apart when you'll remove the log. This ratio is about right for what we try to achieve here.

• Coat your wood log with a touch of oil and then use a brush to coat your log with a first layer of gelatin, making sure to put some into every crack. That will prevent air bubbles to form inside those.
• before anything else, I would suggest to lightly coat your container with oil and add a layer of cellophane before pouring the gelatin, it will prevent gelatin to adhere too much to your container
• Now put you log back on top of the container and fill it with gelatin. Add weight on top of it because gelatin is denser than water, your wood log will float on it.
• Put in the fridge overnight. If you're in a rush don't overfreeze gelatin, it tends to leak water when frozen.

Once hardened, you can stretch the gelatin and take your log out of it

You can reuse the mold for several shells but it will only last a few days in the fridge before fermenting

If you prefer to create a silicon mold, it's actually easier.

to prevent silicon to bond with the wooden surface of your mold, use some release agent. I used petroleum that I applied with a brush before thinning it with a hairdryer. You don't want to much or will will blend the details.

Prepare the silicon following the instructions, I used two parts silicon that I mixed thoroughly.

You can set your log on a flat surface with parchment paper and use a brush to add layers of silicone other the log.

You could decide to dip the log into silicon like I did when making the gelatin mold but this thing isn't cheap.

It's actually easier to brush the silicon when it's starting to set. That or do several batches and add layers once the previous one has set.

Try to put an even coating of about 3mm on all the log except the bottom.

Remove the log from the mould and clean it with soap to remove any leftover release agent.

Now comes the fun part.

Melt some chocolate using for favorite method (you'll find plenty of instructables on how to properly melt chocolate)

I used a combination of dark and milk chocolate for the bark and Blond chocolate for the core of the log. If you can't find blond chocolate (Dulcey by Valrhona) you can mix 2/3 white chocolate and 1/3 milk chocolate. It won't taste the same but look alike.

I tried to put milk chocolate in the cracks of the mold (that are actually the exterior of the bark) using a painter's brush and then cover it with dark chocolate. It's a pain to do.

I ended up putting the dark and milk chocolate in the same bowl and then use a stick to swirl one into the other to create some marble effect. I then poured some into the mold where the bark is supposed to be.

Use the blond chocolate once the bark is done.

Now you're faced with a dilemma. The thinner the chocolate shell the best the end result. But too thin and you won't get it out of the mold. add more chocolate at the jonction between faces.

Watch the videos to see how careful you need to be the release those shells from the molds.

Now you have a chocolate shell you can use however you like.

Here i made a pistachio mousse with a raspberry filling and almond cake.

As you can see, having a thin shell will let you cut the cake without having to use an axe. Even if that would be very cool :)