Many home chefs know that tempering chocolate to achieve a perfect finish and a satisfying “snap” is no easy task. Small variations in ingredient quality, temperature, mixing, and timing can all lead you to failure, even when you’re learning from the best.
The results of a new study by food scientists at the University of Guelph in Canada suggest that adding two common natural fats – in the right proportions – may make tempering chocolate less risky.
Pick up just about any block of milk chocolate at your local store and you’ll find that it’s made up more or less of the same things – cocoa butter for shape, cocoa mass (or chocolate liqueur) for that familiar bitter taste, and additives like sugar or vanilla for sweetness and flavor.
Making a solid chocolate bar is all about encouraging the right size and distribution of crystals. In chocolate, the crystalline forms of cocoa butter triglycerides (TAGs) are what give food its characteristic shine, smooth texture, brittleness and melting point.
Not just any crystal structure will do either. Of the six distinct configurations of this known class of molecules, the V shape is the one that gives us perfect character.
Tempering – turning the diverse mix of molecules into something that resists your bite while feeling divinely gentle on your tongue – is a culinary process that has gradually perfected over time, relying on a refined sequence. heating, mixing and cooling.
While researchers studied the influence of TAG composition on steeping success, little is known about how the minor components in cocoa butter might make or break the process, including things like free fatty acids and phospholipids.
Since they make up only a few percent of the chemicals in cocoa butter, differences in their origins and refinement could dramatically change the makeup of this key ingredient, either by helping the right crystals to be generated or by interfering with their growth.
Previous research has hinted at the roles that certain minor components have in forming ‘seed’ crystals. For example, having a lot of free fatty acids seems to poison the crystallization process. Phospholipids, on the other hand, seemed to help them grow taller.
To determine the precise proportions and chemical nature of these components, the researchers analyzed the exact composition of a sample of cocoa butter, varying its composition by adding ingredients or by bleaching existing ones.
They then put it through various tests to determine how variations in fat content can affect the growth time and proportion of crystal types, as well as things like melting point, surface reflection, microstructure and flexion.
While the amount of molecules such as free fatty acids had some effect, the real game changer was the proportion of phospholipids, especially saturated phosphatidylcholine and phosphatidylethanolamine. Don’t be fooled by the tongue twister names: they are organic molecules from vegetable varieties that are found in the membranes of living cells.
These two molecules at higher concentrations allowed the formation of V-form crystals, giving cocoa butter optimal glass, microstructure and mechanical properties.
Adding the right amount of each to chocolate just might take the anxiety out of the tempering process, either by simplifying it or even eliminating it altogether.
It won’t necessarily make all of us home cooking dessert makers. But for professionals who rely on recipes they can rely on, knowing a little more about the chemistry of their chocolate creations just might give them the formula they need.
This research was published in Nature Communication.