How to produce chocolate
Some chocolate producers have integrated production lines that allow them to start from the raw ingredients: among them are cocoa liquor and cocoa butter. Then, the production of chocolate consists of three main stages : mixing, refining and conching.
Each production step plays a key role in the chocolate’s final harmony of texture and taste.
The ingredient source and quality of cocoa mass, in particular, will be critical for flavor and final product identity. It is the start of the sensory journey.
The chocolate recipe has a limited number of ingredients: cocoa mass, sugar, cocoa butter, milk (for milk chocolate), emulsifier and vanilla flavor.
Step 1: Mixing
Blend all dry ingredients with part of the cocoa butter to obtain a homogenous, powdery paste. At this stage, the quantity of fat has to be well adjusted to the needs of the refining process. Should the fat content be too high, the mix will pass through too quickly and not be refined enough. If the fat content is too low, the “paste” will be very dry, and the refiner yield too low.
This stage consists solely of dry mixing and does not require high shear.
Step 2: Refining
This step is crucial for chocolate smoothness. Cocoa, sugar (or SweetPearl® maltitol for sugar-free version), NUTRIOSE® soluble fiber (for a sugar-reduced version, source or rich in fiber chocolate); and milk needs to be ground to very small particle size.
The human palate can detect particles from 60 µm to even 30 µm in some countries. In most cases, finished particle size will not exceed 30 µm (North America) and 15/22 µm in Europe.
For sugar-free chocolate, replace sucrose with SweetPearl® and follow the same process parameters.
In the refining stage, the chocolate mass will pass through a series roller, resulting in particle size reduction. Alternatively, you can use closed systems with beads or hammers to break down the particles.
Step 3: Conching
The mass exiting the refiner is a powder with no cohesion and is referred to as “flakes.” The conching consists of powder intermingling until the fat is well distributed around each individual solid particle. Consequently, the powder becomes pasty and eventually liquid.
The aroma will develop its fine and delicate notes thanks to the evaporation of the undesired volatiles and moisture.
The conching (= gentle mixing, between 55°C and 80°C depending on the type of chocolate) can last 6 to 24 hours in order to obtain the right texture and taste.
Mass tempering, before molding or enrobing, plays as well an important role in the overall texture of the chocolate and for stability over time.
Key characteristics to measure on chocolate mass are viscosity and yield value or point:
- Viscosity will influence the flow rate, pumping capability, enrobing capacity, and enrobing rate (the excess of high viscosity chocolate will be difficult to blow to lower the coating %), etc.
- The yield value represents the energy required to start the chocolate moving. This value will help to understand the chocolate capacity to maintain a shape, hold a pattern despite the transportation or cooling belt vibrations. As well, it will explain the chocolate tendency to form feet and tails for enrobed centers.
We are not entering here the complexity of cocoa butter crystallization, but chocolate is a very complex matrix that requires know-how to melt perfectly in the mouth.