Liquid Gold AKA Chocolate
Scientifically speaking, food as we know it on our plates is a collection of mixtures—believe it or not, there’s very few processed or natural foods out of supermarket shelves that comprise entirely of a single ingredient. A fine bottle of wine is a mixture of hundreds of volatile compounds and natural grape sediment in an aqueous, alcoholic environment. In (cheaper) comparison, bowls of cereal and milk are heterogenous mixtures of bits of coloured, floating sugar suspended in a liquid. Milk itself is a homogenous colloid, where globules of fat, casein micelles and reducing sugars are held in water, giving it its cloudy appearance. In fact, throughout all my time at the Culinary Institute of America, there is exactly one product I have found that is certifiably 100% of a single ‘ingredient’:
I’m really lying though because goodness knows what’s floating around the inside of a pumpkin/everything’s probably contaminated by Listeria monocytogenes anyway.
Continuing in that vein though, I’ve spent the past few weeks taking a closer look at chocolate, which is about the most heavenly leisure activity I could’ve picked in this apocalyptic mess of a semester. I picked the best partner and the best possible station—making chocolate from bean to bar and using it to come up with a composed plate of food—for a special projects day that, while pretty onerous in nature, allowed for complete expression of creativity, an explosive amount of experimentation and an unparalleled glimpse into the very real world of recipe testing and development in which I eventually hope to sink my teeth into. The immensely collaborative nature of this college and the grace of Chef Peter Greweling (Certified Master Baker, but no pressure or anything) allowed me to explore a world in which I hitherto had little to no experience in, but heaps of admiration for. As I came up with the perfect tart for the day, here are some things I learned about chocolate:
Chocolate is a mixture, which figures because, as I said before, there are no true pure substances in the biodynamic juggernaut that is the world of culinary and confectionary arts, and something about being in a science degree sucks the magic out of everything, even gorgeously fluid melted chocolate. However, contrary to popular opinion (if you’re the kind of nerd that has an opinion about homogeneous mixtures anyway), it is definitely NOT an emulsion, which is best described as a medium where both non-polar and polar molecules are held together over a long period of time, typically with the help of an amphipathic molecule that binds the two together thanks to a maelstrom of electrostatic interactions/hydrogen bonds. It is a colloid (much like milk) with a continuous medium of cocoa butter (so really not like milk at all) in which millions of crushed particles of granulated sugar and cocoa bean particles hover about blissfully. There’s no water there, unless you want to be really pedantic and include any moisture soaked up by the hygroscopicity of sucrose molecules, which Chef Greweling/Cadbury/Hershey all probably do, but I couldn’t care very much about (don’t tell them).
The percentage of chocolate depends on entirely the percentage of cocoa solids included in the original ratio—most people think this means brown bits, but will be COMPLETELY blown away to realize is primarily white bits of cocoa butter, which comprises 55% of the actual bean. This finding remains consistent with the idea of chocolate being a colloidal suspension—while there are mixtures where the continuous phase is significantly lesser than the dispersed phase (*cough* mayonnaise *cough*), this isn’t typically the case—of cocoa particles and sugar in fat, and also debunks all the nonsense out there that white chocolate isn’t actually chocolate. The primary composite of cacao beans is distilled, deodorized and perfumed, often with vanilla, to make the pristine white confection. Stop shaming it.
Processing chocolate from bean to bar is exactly as difficult as it sounds. The beans need to be roasted at a specific temperature long enough to sear off-compounds and develop chocolate’s signature toasty flavors without getting scorched, then need to be cracked open manually in a process that really builds your upper arm strength, and then need to be winnowed (tip: use a hairdryer). After figuring out an appropriate ratio of cocoa beans to cocoa butter to granulated sugar, the colloid is kickstarted by an extremely vigorous process to leach the cocoa butter from the bean’s cellular structure (tip: use a blender) before the chocolate ‘liquor’ is conched and refined for days at a time to grind down particulate size and flood the medium with cocoa butter at a high enough temperature to burn off volatile acids. Oh and then there’s lecithin. It’s hard.
The shape and texture of chocolate depend entirely on the fat (wouldn’t it be wonderful if that’s all the world depended on?) and how the culinarian in question forces it to crystallize. In chocolate, the network of cocoa butter molecules refers to the arrangement of fatty acid chains around a glycerol molecule—the presence of cis or trans bonds between carbons on fatty acid chains, their degree of saturation and length all determine how well they ‘pack’ together, aided by hydrophobic interactions, and, consequently, how the fat melts, appears and is perceived in a bar—cocoa butter is subject to polymorphism: the fat solidifies into crystals of different shapes. From coarsest to finest & increasing order of stability, these crystals are α (alpha), β’ (beta prime) and β (beta)—β crystals are the likeliest to form stable, platelet-like crystals with highly organised, compact structures, a comparatively higher melting point and that provide gloss and sheen to tempered chocolate, best recognised as the fancy garnishes and shiny plaques bordering the most opulent desserts in any viennoiserie. Thermally treating chocolate by heating it to 26-27 °C, agitating to encourage β crystal formation and gently cooling it to inhibit the process is what produces a tempered product, which has a significantly different mouthfeel and appearance than ‘seed’ chocolate.
Chocolate is a specialty. It’s a niche all its own. It gets on absolutely everything and makes it impossible to keep chef whites clean, which has probably short-circuited many an OCD-baker-brain, but understanding it and delving into the composites of this magnificent mixture that has somehow become synonymous with comfort, compassion and late night rom-coms is a process that can take a very long (happy) lifetime. It is culinary science at its very best: a spectacular exhibit of molecules interacting in ways that they really shouldn’t thanks to human intervention, transmuting the humbly dull cacao bean into a versatile, patisserie miracle. It’s going to be the focus of the next three weeks of my life as I audit the class through hell week in the eighth semester and I might not come out alive, but if it means I’ll know how to make truffles and begin chipping at my spectacularly flashy table-top tempering skills, it’s probably worth it.
By Altamash Gaziyani