LABORATORY FOR CHOCOLATE SCIENCE?
What is Chocolate?
Chocolate is a solid mixture. In its basic form it is composed of cacao powder, cocoa butter, and some type of sweetener such as sugar; however, modern chocolate includes milk solids, any added flavors, modifiers, and preservatives.
Cacao is the plant matter which lends the unique tast and bitterness to chocolate. The chocolate mixture is made of aggregations of micro particles of cacao and sugar, and globules of cocoa butter fat milk solids.
The word “chocolate” comes from the Nahuatl word Xocolatl for “bitter water”, referring to its original incarnation as a hot, spiced beverage in the Mayan and Aztec traditions.
What’s in Typical Chocolate?
- 10-20% Cacao
- 8-16% Milk Solids
- 32-60% Sugar
- 10-20% Cocoa Butter
- 1.2% Theobromine and Polyphenols
How is Chocolate Made?
- Harvest: Cut and crack open pods for beans
- Ferment: Let micro-organisms and heat kill bean and develop flavor
- Dry and Ship: Sun dry beans to preserve them for travel to chocolate-making factories
- Clean: Remove dirt, sand, and debris
- Winnow: Remove bean shell from cotyledon (nib), saving the flavorful nib
- Roast: Heat the nib to develop its flavor
- Grind and Mill: Release cocoa butter fat and generate coarse particles of cacao from the nib
- Mix: Combine cacao, cocoa butter, milk, sugar, and flavors
- Conch: Slowly mix ingredients under heat while continuously grinding to make a smooth texture
- Temper: Crystallize the cocoa butter to form a solid that is easy to snap and melts in the mouth
- Form: Pour and cast chocolates
Where Does Chocolate Come From?
Cacao comes from the Cacao Tree, Theobroma Cacao, a member of the evergreen family Sterculiaceae The word “theobroma” literally means “food of the gods”, indicating chocolate’s exalted status in both ancient and modern tastes!
Cacao trees grow in tropical climates with a high degree of moisture. There are three major varieties: Criollo, Forestero, and Trinitario. Criollo trees yield mild, complex chocolate but are less hardy and more rare. Forestero makes up the majority of modern chocolate product, and Trinitario is a hybrid originally from Trinidad that is used as a supplement to Forestero.
Cacao is made from the cotyledons (“seed leaves”, the nibs) of the beans. The beans are found in cacao pods (called cherelles). Every cacao bean is genetically unique!
Cacao pods are usually 200 to 250 g and contain 30-45 beans, They are usually harvested by hand to avoid damage to the beans.
WHY TEMPERING CHOCOLATE?
Well-tempered chocolate should set up with a smooth, lightly glossy finish and a firm snap. Poorly tempered chocolate may appear mottled, spotted, or pale, with a soft, sometimes grainy texture.
With most cooking fats and liquids, there’s a magic temperature above which they’re liquid and below which they’re solid. Simple, right? Chocolate, on the other hand, follows its own set of rules. Sure, it has a melting temperature, but depending on precisely how long it’s been held at a given temperature or how forcefully it’s been agitated, its texture once solidified can vary drastically.
Why is this? It’s because cocoa fat, the primary constituent in chocolate that gives it its solid texture, can form various types of crystals ranging from loose and unstable to well-structured and firm. Tempering is the process of heating chocolate to a series of precisely defined temperatures and working it in order to maximize its chances of forming a tight, stable structure.
Sounds confusing, right? But it’s actually pretty simple. It helps to think of cocoa fat as a bag that’s filled with lego bricks along with an army of elves on-call to snap them together. The goal is to get those elves to assemble all of the lego bricks into a solid, stable wall. Depending on the temperature range at which you hold the chocolate, these bricks get assembled in different ways.
115°F and above (46°C): it’s simply too hot for those elves to work.
The chocolate is completely melted, and no structure will be formed.
88 and 92°F (31 to 33°C) you’ve got ideal working conditions. The elves work
together, adding bricks a few at a time to the wall, starting from the bottom up,
eventually building a nice, solid structure.
88°F (31°C) and below: the cold distracts the elves. Rather than working as a team,
they start to work individually, snapping together bricks as fast as they can.
The end result is a disorderly mess of masses of different shapes and sizes,
none of which can be put together into a solid structure.
Put into pure chocolate terms, when you heat chocolate above 115°F, it melts completely. Lower the temperature too rapidly and you’ll end up forming very unstable crystals, creating chocolate that doesn’t firm up properly and has a dull appearance. If, on the other hand, you hold it in that magical 88 to 92°F long enough for most of the cocoa fat molecules to align themselves properly.
CHOCOLATE SCIENCE – FAT composition
Most fat in chocolate is cocoa butter.
CHOCOLATE SCIENCE – COCOA BUTTER CHEMISTRY
Given the structure of cocoa butter, with two fatty acid “arms” on one side and the third on the other, how many different ways can you think of for the molecules to pack together?
CHOCOLATE SCIENCE – PHASES OF CHOCOLATE and best temperature
Chocolate goes through phases. From phase 1 (18 degrees C) to phase 5, which is best for chocolate (34 degrees C).