Next time you see your favorite craft chocolate maker, give him or her a hug. They need it. For them, every single day is a real grind. They have to keep their noses to the grindstone in order to bring you great chocolate.
Why? Grinding is an essential process in making chocolate. After the cocoa beans are roasted, cracked and winnowed (these processes are covered in other blog posts), the resulting cocoa nibs (chunks of the interior of a cocoa bean) must be ground until they become liquid chocolate.
To achieve the smooth consistency we expect from fine chocolate today, the nibs (and any added sugar) must be reduced in size to particles measuring about 20 microns or less. That's tiny! Your eyes cannot see particles that small, and your mouth can't feel them. For comparison, the average particle size of a grain of wheat flour is about 30 microns. Human hair is usually between 40 and 150 microns thick.
It wasn't always this way. Chocolate was first ground on stone slabs by hand. In some places today, this traditional method is still used. As you might expect, the result of hand-grinding is more coarse, and if sugar is involved, pretty gritty. But given the choice between gritty chocolate or no chocolate, I know which one I would choose! Note: If your craft chocolate maker grinds your chocolate by hand this way, then he or she gets two hugs!
When cocoa nibs are ground, the cell walls of the nib are broken open, and cocoa butter that has been hiding inside is released. Liquid chocolate is really a suspension of bits of the cell structure floating in cocoa butter. If the cocoa butter was pressed out of this suspension, the remaining product would be cocoa powder!
Sugar: The Problem Child
Given its plant-based cellular structure, the cocoa nib is actually the easier part of the mix to work with. Sugar, on the other hand, is a hard crystal, and tough to grind down to size. Depending on the grinding method, sugar can take hours or even days to crush to the appropriate size. And the friction of grinding sugar produces a large amount of heat.
Your craft chocolate maker has a lot of choices for how to accomplish all this grinding. There are impact mills, roller mills, ball mills, or granite wheels - all of which grind in different ways with different outcomes. Sometimes, more than one grinding method is used. The chocolate maker chooses the grinding method that best achieves the maker's vision for the finished product.
So now the nibs and sugar are ground down to size, and we have liquid chocolate. We're finished, right? Well, usually not. There's another step involved, called conching. (Conching is technically not part of the grinding process, but it usually follow grinding so closely that we're going to talk about them together.)
Conching is an extended stirring, sometimes with an added heat source. Conching accomplishes two goals. First, it ensures that all of the now-tiny cocoa and sugar particles are evenly coated with cocoa butter - for that melt-in-your-mouth sensation when you eat the chocolate. Second, conching drives away some remaining volatile (vinegar-y) compounds that don't taste very good.
Why is it called conching? The very first conching machine resembled a conch shell - home to the tasty sea creature. The newly-invented process was named after the shape of the machine. The conche machine was invented less that 150 years ago, so the smooth chocolate bars we know today are a relatively recent development. It really makes you wonder how humankind survived and progressed prior to the invention of conching!
So hopefully you can see now why making chocolate is such a grind. And why your favorite craft chocolate maker deserves a hug for dealing with it every day. Just another reason to love them - and the great chocolate they make!
Comment and let us know if you have other questions about chocolate. Watch for future installments in our Crafting Chocolate series.