Tempering of Chocolate

In order for chocolate to possess the desirable qualities needed for use in mass production, it has to go through a process called tempering which encourages the crystals in the cocoa butter to form and harden in a specific crystalline pattern. When melted and cooled, the fats in chocolate can crystallise into any one of six different forms and only one of these possesses all of the desirable qualities we look to achieve in chocolate tempering. The Beta Crystal or Form V hardens into the firm, shiny chocolate we know. Un-tempered chocolate will often not set completely at room temperature, and if it does, it may become susceptible to fat bloom or become dull on the surface with a somewhat spongy texture. Fat bloom refers to the fats in the chocolate migrating to the surface and creating white-looking streaks and blotches.

Cocoa butter is fat that is composed of three to four glycerides of fatty acids. What complicates matters in chocolate making is that each of these different fatty acids solidifies at a different temperature. Once you melt a chocolate bar, the fatty acid crystals separate. The objective in tempering melted chocolate is to entice the disparate fatty acid crystals of cocoa butter back into one stable form. Tempering is like organizing individual dancers at a party into a Conga line. For chocolate, temperature and motion are the party organizers that bring all the individual dancing crystals of fatty acids together in long lines and, in the process, create a stable crystallization throughout the chocolate mass.

In the tempering process, melted chocolate is first cooled, causing the fatty acid crystals to form nuclei around which the other fatty acids will crystallize. Once the crystals connect, the temperature is then raised to keep them from solidifying. Most cooking literature advises you not to get the chocolate over 120°F (49°C) for fear of burning the cocoa solids, or causing the chocolate to irreversibly separate into solids and fat. But melting curves of chocolate in the technical literature indicate that most of the fats in cocoa butter aren't melted until 122°F (50°C), and some processors recommend heating their chocolate even higher—up to 131°F (55°C).

Cocoa beans from different locations vary: at the same temperature, cocoa butter from Malaysian beans grown near the equator will be firm, while cocoa butter from Brazilian beans grown in a cool climate will be very soft. General stages of ALL tempering methods:

Stage 1 – melt all cocoa butter, changes for every manufacturer

Stage 2 – rapid cooling, starts crystallisation of good beta crystals as well as some beta-primes

Stage 3 – slight warming, held for a few minutes, continued formation of beta-crystals

Stage 4 – final warming, melts undesirable beta-primes

Methods of tempering:

1. Seeding – adding already tempered chocolate at room temperature to melted chocolate to bring down the temperature and help form beta-crystals.
2. Marble slab – the use of a marble slab and the constant movement of chocolate is considered a traditional method of tempering in this day and age.
3. Using a microwave – considered highly effective, even preferential by some. Can burn chocolate easily.
4. ‘Mycro’ – something of a cheat’s tempering, a powder that is added to melted chocolate to give the qualities of tempered chocolate.