How does non-melting chocolate work? A look the methods of creating non-melting chocolate and the use of cocoa butter alternatives.

I spent the majority of my childhood in Australia, so naturally I grew with Australian chocolate: the taste, texture, and most importantly its resistancy to melting in the hot climate.

When I was 8 years old I visited the UK and had my first taste of UK chocolate. While Australian chocolate is waxy and can form insoluble clumps in your mouth, UK chocolate has a thicker, richer consistency. While Australian chocolate refused to melt even in 40 degree heat, UK chocolate could melt in the palm of my hand.

I began to wonder: how could two products under the same brand name react so differently to the same conditions and what causes this?

So how does non-melting chocolate work?

Method 1:

In this method, chocolate manufacturers use fats with higher melting temperatures in the chocolate. Traditional cocoa butter melts at just below the human body temperature which is why chocolate tends to melt if you hold it too long. By using fats with higher melting temperatures, chocolate can be kept in much higher temperature areas and retain its usual shape and texture.

However, the other side of not using cocoa butter means the chocolate can have an unpleasant taste or consistency (such as a waxy aftertaste in the mouth)- something commonly found in Australian chocolate.

These fats with higher melting temperatures are often called “Cocoa butter alternatives” and can be classed as:

“Non-cocoa derivatives that can be used to replace a portion or entirely from the usage of cocoa butter in a chocolate product.”

These alternatives to cocoa butter fall into 3 primary categories:

1. Cocoa Butter Substitutes (CBS)
2. Cocoa Butter Replacers (CBR)
3. Cocoa Butter Equivalent (CBE)

Cocoa Butter Substitutes (CBS)

• Palm oil or coconut oil based.
• Contains lauric fatty acids. (C₁₂H₂₄O₂ white powder)
• Lauric fat in the presence of enzymes like lipase (found in cocoa beans), under the right conditions (moisture, temperature), can react and produce a soapy taste.

Cocoa Butter Substitutes are not compatible with cocoa butter. This means you cannot mix them together with cocoa butter in chocolate which means the chocolate produced will exhibit more sideaffects like texture changes and “soapy” tastes.

Cocoa Butter Replacers (CBR)

• Non-lauric containing fats like palm oil, soybean oil, rapeseed oil and cottonseed oil.

Cocoa Butter Replacers are partially compatible with cocoa butter. This means they can be mixed with cocoa butter in the chocolate but only in small amounts.

Cocoa Butter Equivalent (CBE)

• Can contain shea, illipe, and sal nut oils as well as palm, mango kernel fat and palm oil.
• Has physical properties and a fatty acid profile similar to cocoa butter.

Cocoa Butter Equivalents are wholely compatible with cocoa butter and are most similar in properties to cocoa butter. This means chocolate can be made from a combination of cocoa buter and Cocoa Butter Equivalents, reducing the taste and texture differences between normal melting chocolate and the new non-melt chocolate

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Tempering

Tempering is a process of melting chocolate to give it ideal properties like gloss (the shiny outer appearance of chocolate) and snap (the satisfying crack when pieces are snapped from a chocolate bar). Many cocoa butter alternatives do not require tempering (except Cocoa Butter Equivalents as they are most similar to cocoa butter), it’s easier to achieve these essential texture characteristics like gloss and snap.

Fat Blooms

Using cocoa butter alternatives can also reduce the chance of “fat blooms”- a whitish coatings on the surface of chocolate due to a change in fat crystals in the chocolate. These fat blooms diminish the appearance of the chocolate and the chocolate’s shelf life (although still safe to eat).

These fat blooms are due to cocoa butter separating from the surface and can be due to many different reasons, such as poor storage, and poor cooling and tempering methods.

There are two main theories as to what causes fat blooms:

1. Phase separation theory. Different fats in cocoa butter have different melting temperatures so all melt slightly differently under heat, leading to the formation of fat blooms
2. Polymorphic transformation theory. Cocoa butter has 6 different “polymorphic forms” (different crystal structure shapes). Fat blooms occur when the shape changes from one structure to another, often to the most stable form (form 6).

Overall

The use of these cocoa butter alternatives is relatively limited in the EU as only 5% of vegetable fats can be used instead of cocoa butter for the product to be allowed to be called “chocolate”, and in the US the Food and Drug Administration (FDA) states that a chocolate product containing vegetable fats must be called “chocolate flavor” instead.

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Method 2:

In 2014, Cadbury’s official patent application stated their method of producing high-temperature resistant chocolate by adapting the “conching step” of chocolate production.

Normal chocolate begins melting at just lower than body temperature (around 30-32 degrees C) but their patent application Cadbury’s scientists described a method for dramatically improving chocolates resistance to heat so it would remain solid even if left in 40 degrees C heat for up to three hours.

What is conching?

“Conching” is the process of heating and mixing together the ingredients of chocolate – cocoa, cocoa butter, sugar, lecithin (a generic term for yellow-brown fatty substances in the body that are body hydrophilic (attracting water) and lipophylicc (attracting fatty substances)) as well as any flavourings such as vanilla or essential oils. This process ensures that cocoa butter is evenly distributed among the chocolate.

Air flowing through the conche can removed unwanted acids (such as butyric, acetic and propionic) from the chocolate. If left in the chocolate, these acids can cause an excessively bitter taste. This air also brings oxygen to the chocolate mixture. The oxygen can oxidise substances produced in the roasting of the cocoa beans, mellowing the flavour of the product (making the chocolate less harsh to taste).

Furthermore, conching reduces the moisture in the chocolate. This is desirableincreased moisture leads to an increased negative impact on chocolate viscosity (lower viscosity the chocolate will have a thinner, runnier consistency). Increased water content is also bad for the chocolate as the “flavor particles” in the chocolate mixture are mainly polar while the fat is non-polar. Water, being polar, is more likely to mix with the flavor particles than the fat. The flavour particles will dissolve in the water and form clumps in the chocolate in a process called “seizing”.

By adapting the conching technique the Cadbury scientists were able to “shear” sugar particles down (make smaller) which means they are covered with less fat, making the bar less easy to melt.

So how did the Cadbury scientists adapt the conching technique?

Well, Cadbury scientists introduced “refining” the conched chocolate after the conching step.

Refining is the final grinding of all particles in the liquid chocolate together to produce an even extremely smooth texture in which no grit can be detected on one’s tongue or pallet. So while conching’s primary aim is mixing, refining ensure that the sugar particles are as small as possible. The two processes can be achieved using the same machine.

During the refining process the sugar particles are broken down small enough to be measured in micrometres (1 x 10^-6 – for comparison a human blood cell is about 5 micrometres in width so these particles are pretty tiny). It is this incredibly small particle size that holds the secret to this method of making non-melting chocolate.

As I am currently living in England and the temperature never rises above 20 degrees on the hottest days the chocolate here is yet to need this food technology and, based on my personal experience, the waxy feel left over after eating non-melt chocolate in Australia, I hope we never do.

Thank you for reading this post!