Chocolate: From Bitter Bean to Melty Bar Explained

Nova: Buckle up, Explorers.

Cosmo: Brains in!

Nova: Wheels up!

Nova & Cosmo: Brain Bus, let's GO!

Nova: You're on The Brain Bus - I'm Nova, your driver, and today Cosmo and I are taking you somewhere delicious.

Cosmo: I'm Cosmo, robot co-pilot and self-declared snack expert, and I have been looking forward to this one since we left the depot.

Nova: Explorers, here is your first fact, and it is a big one. The chocolate in your favourite candy bar started out as a bean so bitter and yucky - you would spit it RIGHT back out.

Cosmo: Spit it out?! But it's CHOCOLATE.

Nova: Not yet, it isn't. Today on The Brain Bus we are following a cacao bean - that's the seed that becomes chocolate - all the way from a jungle tree through a whole wild adventure until it turns into the smooth, melty thing you know and love. Hold on tight.

Cosmo: I am already hungry. Let's go.

Nova: Picture a tree in a warm wet jungle - not an apple tree, not an oak. This one has bright pods growing right out of the trunk and thick branches, not on little twigs. Green ones, yellow ones, red ones, even purple ones. These are cacao pods, and this is where chocolate begins.

Cosmo: Nova, those colours - this is the best giant chocolate egg tree in the universe. You crack it open and warm liquid chocolate pours straight out, right?

Nova: Explorers, warm liquid chocolate inside - what do you think?

Nova: What is actually inside is sweet white goo that tastes like fruit - tangy, a bit like lychee - and nothing like chocolate at all. The bitter beans are wrapped in that goo, and those beans are the start of every chocolate bar ever made.

Cosmo: White fruity goo. Okay. That IS interesting.

Nova: Now here comes the most surprising step. The beans go into a big warm pile and sit there and actually bubble for several days. Tiny invisible helpers called microbes - living things so small you cannot see them - move into that warm wet pile and start changing the beans from the inside. Scientists call this fermentation - that means tiny living things transforming something's flavour. This is where the chocolatey taste first begins to appear. The warm bubbling pile even smells incredible - yeasty and sweet and alive.

Cosmo: So it is a microscopic invisible bean party building all the flavour. I respect it deeply.

Nova: After fermentation the beans are spread out in the sunshine to dry for days, then get roasted - tumbled in big warm drums until they finally, actually smell like chocolate.

Nova: Then the roasted beans are cracked open, crushed into a thick paste, mixed with sugar and sometimes milk, shaped, and cooled. Out comes a chocolate bar. Making chocolate is like baking cookies - the ingredients are not yummy alone, but each step transforms them, and only at the very end does something delicious appear.

Cosmo: Nova - how many beans does one bar even take?

Nova: About a hundred. Each pod holds just a couple of handfuls, so many pods go into every single bar.

Cosmo: A hundred beans. I am going to feel very grateful next time.

Nova: Now here is some history I love. The Maya people of Mesoamerica - a part of the world now called Mexico and Central America - grew cacao and drank it thousands of years ago as a frothy, bitter drink. And the Maya are living peoples today, still across Mexico and Central America.

Cosmo: They drank it? Before bars even existed?

Nova: Long before bars, yes. And the Aztec people - who called themselves the Mexica - valued cacao so much they used the beans as actual money. You could count cacao beans out and pay for things with them.

Cosmo: That is the most delicious economy I have ever heard of.

Nova: The Mexica told a story that their feathered-serpent god Quetzalcoatl - ket-sahl-koh-AH-tul - brought the cacao tree down as a gift for people, teaching them to roast and grind the beans into a special drink called xocolatl - shoh-koh-LAH-tul - in their language Nahuatl. Because cacao was seen as a heavenly gift, it was used in sacred ceremonies and treated with enormous respect. The scientific name for the cacao tree, Theobroma - thee-oh-BROH-mah - even means "food of the gods."

Cosmo: Food of the gods. Yeah. That completely tracks.

Nova: And Cosmo - you mentioned before we boarded that dogs would probably love chocolate too.

Cosmo: It smells incredible. Surely dogs want in.

Nova: Chocolate can actually make dogs really sick, so we always keep it away from pets. Chocolate has a natural chemical called theobromine - thee-oh-BROH-mine. Our bodies clear it out easily, but a dog's body processes it much more slowly, so even a small amount causes real trouble. Different bodies, different rules - a treat for us, trouble for them.

Cosmo: Filed. No chocolate for dogs. I will defend this rule forever.

Nova: Explorers - just sit with this for one moment.

Nova: Chocolate doesn't grow as chocolate. It starts as bitter beans on a tree, and people change it step by step - all that bubbling, drying, roasting, mixing - until it turns into something sweet. Every single step matters. People figured that out thousands of years ago and never stopped marvelling at it.

Cosmo: QUIZ TIME, Explorers! Three questions - shout your answers out loud!

Nova: Question one - True or False: fresh cacao beans taste sweet like candy.

Nova: FALSE! The sweetness is added later by people, which is exactly why so many steps are needed.

Cosmo: Question two - True or False: cacao pods can be red, yellow, or purple.

Cosmo: TRUE! The colour tells farmers how ripe the pod is - like a traffic light growing right on the tree.

Nova: Question three - long ago, the Mexica people used cacao beans as: (a) money, (b) toys, or (c) hats?

Nova: It is (a) - money! The beans were so precious people counted them out like coins to pay for things.

Cosmo: Explorers, whether you got one right or all three - you played this quiz by thinking, and that is the whole point. Every single one of you nailed it.

Nova: Fun Fact Blast - four facts, fast!

Cosmo: Long ago people drank chocolate as a bitter frothy drink - and sometimes they mixed in spicy CHILLI!

Nova: Chocolate bars are actually brand new in the big story of chocolate - for almost all of its history, there were no bars, just the drink.

Cosmo: Chocolate melts perfectly on your tongue because it melts at almost exactly the same warmth as your body - your mouth is literally the perfect temperature!

Nova: And in Australia, there is a small patch of real cacao trees growing near the Daintree rainforest in Far North Queensland, close to Mossman - real Aussie-grown chocolate beans actually exist.

Cosmo: The Daintree. Adding it to my travel list immediately.

Nova: Okay Explorers - eyes closed if you like, unless you are the one driving, obviously!

Nova: Imagine you are a tiny cacao bean on the biggest journey of your life. You start snuggled inside a colourful pod pressed right against the tree's trunk. Someone carefully scoops you out - you are covered in sweet white goo. Then you rest in a warm pile with all your bean friends and bubble away for days. Then you dry slowly and quietly in the sunshine. Then you get roasted, warm and toasty, in a big turning drum. Then you get cracked open, crushed, and mixed with sugar. And at the very last step - you are smooth, melty chocolate.

Nova: Try saying all those steps out loud with the people in your car. Bubble - dry - roast - crush - mix - chocolate! See if everyone can do it together without peeking at any clues.

Nova: Here is your wondering question: why do you think people kept doing ALL those steps instead of just eating the bean straight off the tree?

Cosmo: Next-Stop Riddle time!

Nova: Listen carefully, Explorers. Here comes your riddle for next time.

Nova: I can turn a straight line into a squiggle, I can make a short wall look tall, I can fool your eyes into seeing things move - when nothing is moving at all. What am I?

Nova: Have you got a guess? Hold it tight - because we are NOT telling you the answer today. You will have to climb back on The Brain Bus to find out!

Cosmo: I have a very strong theory. I am keeping it entirely to myself.

Nova: Explorers, today we went from a bitter little bean on a jungle tree all the way to a melty chocolate bar - and it turns out that chocolate is one of the most patient, most worked-for, most treasured treats on Earth. The Maya drank it, the Mexica used it as money, and every bubble and sunny day and roasting drum still goes into every bar made today. That is worth remembering next time you take a bite.

Nova: Stay curious, stay clever, and keep that brain working!

Nova: Until the next stop, Explorers...

Cosmo: ...keep wondering.