Process 12: Tempering 1

Hello my fellow chocolate lovers,

I am Takanori Chiwata, the chocolate engineer of COCONAMA CHOCOLATE.

Today, we will be talking about “tempering”.

For those who are reading this blog with a strong interest for chocolate may be familiar with the term “tempering”.

Tempering is a process used to adjust the temperature of chocolate.

To put it simply, tempering is a process to cool down chocolate down to about 26℃ and then to gradually heat it back up to about 29℃ before hardening it.

Without a proper tempering process, the chocolate would lack its nice and glossy finish.

It will look something like the image shown below.

Why is that the chocolate will lose its gloss without a proper tempering?

Don’t we all want to end up with a nice glossy chocolate?

As I mentioned last time, chocolate is something that has sugar and other ingredients scattered inside its cacao butter.

This cacao butter crystallizes differently depending on its temperature.

The cacao butter can crystallize in 5 different forms under 15℃,19℃,23℃,25℃ and 28℃.

We call the cacao butter at 15℃ and 19℃ the I form and II form, and it will crystallize into a hexagonal prism.

We call the cacao butter at 23℃ and 25℃ the III form and IV form, and it will crystallize into a cubed prism.

We call the cacao butter at 28℃ the V form, and it will crystallize into a diamond shaped prism.

The I and II forms are both very fragile, and they could melt as soon as they crystallize.

Compared to that, the III,IV and V forms are firm, so without a proper tempering, all the crystallized cacao butter will be visible.

Well, would there be any problems if the cacao butters are crystallized into different forms?

Before we get to that, do you all know what kind of state a nice, glossy chocolates are in?

When you put a glossy chocolate under a light, it reflects the light nicely like a mirror.

The key to a glossy chocolate is for it to have a flat surface.

This is the kind of image you will see when you look at a neatly lined cacao butter crystals under a microscope.

Each square is one cacao butter crystal.

With a flat surface like this, the lights reflect towards the same direction, so it appears glossy to the naked eyes.

If the chocolate is formed by many different forms of  crystals, the surface of it will be bumpy.

Something like the image shown below.

Just as shown on the image, the bumpy surface scatters the reflections to different angles.

We call this “diffuse reflection” and it appears whitish to naked eyes.

This is what causes the chocolate to become like the one shown on the first image.

A good example for this phenomenon from your everyday life is a frosted glass.

It lacks the nice,glossy finish doesn’t it?

Just like a frosted glass, without a proper tempering, the chocolate will end up with a bumpy surface and without its gloss.

On top of that, a chocolate with inconsistent forms of cacao butter crystals will create problems not just for the surface,but the interior as well. 

The inconsistent lining of cacao butter crystals will cause some parts to melt too fast and some too later. This ruins one of the important characteristics for a chocolate, the smoothness.

That’s why we cool down a chocolate to create the forms III, IV,and V, then to raise the temperature to melt the forms III and IV, leaving the most firm form V in tempering process.

The graph below shows the change in temperature during the tempering process.

Follow this graph and you will end up with a beautiful, glossy chocolate!

Were you able to get a grasp of the purpose of tempering?

I talked about adjusting the temperature during the tempering process, but there are many ways to temper chocolates.

Next time, I will be going to introduce “different ways temper chocolates”. Don’t miss it!

With hopes that you will be able to encounter the perfect chocolate just for you,

Takanori Chiwata