WEBVTT - How Is Chocolate Made? 0:00:01.910 --> 0:00:07.430 Welcome to BrainStuff, a production of iHeart Podcasts. Hey BrainStuff, 0:00:07.510 --> 0:00:12.369 Lauren Vogelbaum here. If you love chocolate, you're far from alone. 0:00:13.070 --> 0:00:16.729 The cocoa and chocolate industry boasts a stunning worldwide value 0:00:16.850 --> 0:00:18.209 of more than $ 178 billion a year, driven by farmers' 0:00:18.250 --> 0:00:26.550 production of some 4.7 million metric tons of beans. That's 0:00:26.770 --> 0:00:29.350 not shabby for a product that was local to a 0:00:29.430 --> 0:00:32.590 narrow band of the Americas for thousands of years and 0:00:32.630 --> 0:00:35.589 really only existed in drink form until the late 1600s. 0:00:37.170 --> 0:00:41.490 As of 2026, Americans eat some 8.4 pounds of chocolate 0:00:41.530 --> 0:00:45.070 a year per capita. That's nearly four kilos. But they 0:00:45.110 --> 0:00:47.940 aren't the winners by far when it comes to chocolate consumption. 0:00:48.350 --> 0:00:51.380 That honor goes to the Germans at almost 18 pounds 0:00:51.479 --> 0:00:56.410 or eight kilos a year. So how did we get here? Today, 0:00:56.650 --> 0:01:01.500 let's talk about the history and science of chocolate. Nobody 0:01:01.560 --> 0:01:04.200 knows when the first person looked at the cacao tree 0:01:04.280 --> 0:01:07.920 and decided to eat its seeds. But anthropologists have found 0:01:08.020 --> 0:01:11.880 evidence of theobromine, a chemical indicator of cacao, in ceramics 0:01:11.959 --> 0:01:13.940 in what's now Ecuador, in the northern part of the 0:01:14.000 --> 0:01:19.750 Amazon River Valley, dating back some 5,300 years. The delicate 0:01:19.770 --> 0:01:22.630 cacao tree grows no taller than 25 feet or 8 0:01:22.630 --> 0:01:26.870 meters and will only grow in tropical rainforest-type conditions where 0:01:26.890 --> 0:01:30.320 it can get lots of warmth, rain, and shade. Unlike 0:01:30.380 --> 0:01:32.860 lots of more temperate trees that dangle fruit from their 0:01:32.900 --> 0:01:36.600 branches among their leaves, the cacao tree blossoms with clusters 0:01:36.680 --> 0:01:39.339 of white to yellow to pink flowers directly on its trunks. 0:01:40.440 --> 0:01:43.500 Researchers think that prior to human cultivation, this might have 0:01:43.910 --> 0:01:46.560 plant spread by keeping the fruit in reach of large 0:01:46.610 --> 0:01:49.240 mammals that could have eaten it and dispersed its seeds. 0:01:50.260 --> 0:01:53.920 Cacao fruits, often called pods, are largish and oblong, sort 0:01:53.960 --> 0:01:58.100 of like a slightly deflated rib football. That's the American football, 0:01:58.180 --> 0:02:01.419 not a soccer football. They can be green or yellow 0:02:01.580 --> 0:02:04.110 or orange or red as they grow, and they'll shift 0:02:04.120 --> 0:02:07.610 to deeper colors as they ripen. Unlike many fruits, they 0:02:07.630 --> 0:02:10.230 can grow year-round, and a single tree will usually have 0:02:10.270 --> 0:02:13.880 a bunch of pods at different stages of growth. Inside 0:02:13.900 --> 0:02:16.900 the pod, there's a sort of gooey white pulp surrounding 0:02:16.980 --> 0:02:21.100 some 20 to 50 seeds, the cocoa beans. The pulp 0:02:21.160 --> 0:02:23.639 is edible, and what I've had of it tasted really 0:02:23.840 --> 0:02:28.179 sweet and tropical. This was probably the first cacao product 0:02:28.240 --> 0:02:31.940 that people ate, either fresh or perhaps slightly fermented into 0:02:32.000 --> 0:02:35.760 a slightly alcoholic drink. But those seeds are what caught 0:02:35.800 --> 0:02:39.139 the world's attention. Fresh from the pod, the seeds are 0:02:39.220 --> 0:02:41.260 light in color and don't have a lot of flavor. 0:02:42.280 --> 0:02:44.260 To get the chocolate we know today, they have to 0:02:44.300 --> 0:02:50.270 be fermented. Yes, chocolate is a fermented product. That fermentation 0:02:50.370 --> 0:02:53.030 generally happens right on the farms where cacao is grown. 0:02:54.050 --> 0:02:56.030 When the pods are ripe, the spotting of which is 0:02:56.070 --> 0:02:58.850 a job for experienced farmers, they're cut from the tree 0:02:58.889 --> 0:03:02.460 by the stem. Farmers then split open the hard pods 0:03:02.590 --> 0:03:05.139 and remove the beans plus some or all of the pulp. 0:03:06.340 --> 0:03:08.640 The workers lay out the pulpy beans in heaps or 0:03:08.680 --> 0:03:11.400 boxes and cover them to help keep them warm and moist. 0:03:12.400 --> 0:03:14.780 The pulp will liquefy, and the beans soak in that 0:03:14.880 --> 0:03:17.940 broth for five to seven days, with workers stirring and 0:03:18.000 --> 0:03:21.820 draining them occasionally. During the first day, the seeds actually 0:03:21.880 --> 0:03:25.710 germinate and begin growing, and those wee baby plants' enzymes 0:03:25.770 --> 0:03:29.549 will convert all of the pulp's sucrose to glucose and fructose. 0:03:30.430 --> 0:03:34.630 With that high-energy food available, a bunch of friendly bacteria, yeasts, 0:03:34.740 --> 0:03:38.710 and other fungi go to town. Those microorganisms get in 0:03:38.750 --> 0:03:41.280 there thanks to contact with the workers' hands and all 0:03:41.300 --> 0:03:45.260 of the equipment that's used and reused. The microbes also 0:03:45.320 --> 0:03:49.060 produce heat, which can reach 122 Fahrenheit or 50 Celsius, 0:03:49.300 --> 0:03:51.930 and is enough to kill the plant embryo and basically 0:03:52.030 --> 0:03:58.390 any unwanted microorganisms. Among the wanted microorganisms are Saccharomyces cerevisiae, 0:03:58.870 --> 0:04:01.550 which is the same species that brewers and bakers use 0:04:01.630 --> 0:04:05.840 for beer and bread. and various species of Lactobacillus, aka 0:04:05.960 --> 0:04:09.880 lactic acid bacteria. The yeasts help break down the pectin 0:04:09.960 --> 0:04:13.460 covering the seeds, which lets two bitter compounds leak out 0:04:13.780 --> 0:04:16.480 and allows the alcohol created by the yeasts to seep in, 0:04:16.820 --> 0:04:19.400 along with all kinds of flavor compounds that are also 0:04:19.490 --> 0:04:23.250 excreted by the microbes. You want to stop the process 0:04:23.350 --> 0:04:26.850 before microbes begin growing in or on the beans instead 0:04:26.870 --> 0:04:29.870 of just the pulp. because those bacteria and fungi can 0:04:29.930 --> 0:04:32.120 break down some of the fats in the beans and 0:04:32.160 --> 0:04:35.980 cause weird, off flavors. So, next, you dry the beans out. 0:04:37.120 --> 0:04:40.080 This process, along with the subsequent roasting to kill off 0:04:40.140 --> 0:04:42.490 any remaining microbes and bring out a lot of chocolate's 0:04:42.580 --> 0:04:45.890 flavor and aroma compounds, is more or less what humans 0:04:45.910 --> 0:04:48.990 have been doing to process rock cow beans into something 0:04:49.010 --> 0:04:54.789 we'd want to consume since about 1900 BCE. By then, 0:04:54.950 --> 0:04:58.330 pre-Omec peoples living in what's now Mexico were taking those 0:04:58.370 --> 0:05:02.120 roasted beans, grinding them, and mixing the resulting paste with water, 0:05:02.380 --> 0:05:06.180 and sometimes ground corn, to make bitter and invigorating beverages. 0:05:07.839 --> 0:05:11.020 Over 3,000 years later, when Europeans showed up in the area, 0:05:11.420 --> 0:05:14.210 the Nahua word for this drink was jocoa, thought to 0:05:14.270 --> 0:05:18.040 mean bitter water. The peoples of the Triple Alliance, sometimes 0:05:18.080 --> 0:05:21.440 called the Aztec Empire, still added ground corn, along with 0:05:21.500 --> 0:05:24.560 spices like chili, vanilla, other herbs, and maybe a bit 0:05:24.580 --> 0:05:28.350 of honey for flavoring. By that time, this drink was 0:05:28.470 --> 0:05:31.450 out of reach for everyone except the upper classes and nobles, 0:05:31.870 --> 0:05:35.870 and associated with important events and ceremonies. The beans were 0:05:35.910 --> 0:05:38.110 one of the forms of currency of the day. They 0:05:38.130 --> 0:05:42.220 were also sometimes used in medicines. Spanish colonizers of the 0:05:42.980 --> 0:05:45.020 1500s brought the drink back with them to Europe, where 0:05:45.040 --> 0:05:49.930 the aristocracy mixed it with another expensive import, sugar. By 0:05:49.950 --> 0:05:54.010 the early 1600s, drinking chocolate was fashionable among, again, the 0:05:54.050 --> 0:05:57.710 wealthy and nobility all across the continent, which means that 0:05:57.790 --> 0:06:01.930 before coffee or even tea, chocolate was the original stimulant 0:06:01.970 --> 0:06:06.450 drink in Europe. More European countries planted cacao trees in 0:06:06.470 --> 0:06:10.510 their own territories around the equator. These plantations and those 0:06:10.550 --> 0:06:14.210 that provided sugar ran off of enslaved labor, the horrors 0:06:14.250 --> 0:06:17.630 of which allowed chocolate to become affordable to and popular 0:06:17.670 --> 0:06:21.109 with the everyday people of Europe and its colonies, especially 0:06:21.210 --> 0:06:24.990 in North America. But remember, this was still a drink, 0:06:25.270 --> 0:06:28.560 and a gritty, unrefined one at that, until a series 0:06:28.620 --> 0:06:33.500 of inventions during the Industrial Revolution changed chocolate forever. And 0:06:33.620 --> 0:06:35.640 we're going to get into that, but first we're going 0:06:35.660 --> 0:06:37.560 to get into a quick break for a word from 0:06:37.580 --> 0:06:48.380 our sponsors. And we're back. Okay, so, in 1828, a 0:06:48.440 --> 0:06:51.240 Dutch chemist by the name of Conrad Johannes van Houten 0:06:51.440 --> 0:06:54.170 figured out how to press the cacao beans to separate 0:06:54.190 --> 0:06:58.190 the seeds' fats, cocoa butter, from the flavorful cocoa solids, 0:06:58.370 --> 0:07:02.050 which is dry cocoa powder. He also treated the cocoa 0:07:02.070 --> 0:07:06.990 with alkali, making it smoother and less bitter. This Dutch-processed 0:07:07.029 --> 0:07:10.810 cocoa was later taken by Englishman Joseph Fry, mixed with 0:07:10.880 --> 0:07:13.660 sugar and some additional cocoa butter, and pressed into a 0:07:13.720 --> 0:07:19.700 mold to make the first solid chocolate bar in 1847. Then, 0:07:20.220 --> 0:07:24.500 in 1879, Swiss inventor Rudolf Lindt developed conching, a machine 0:07:24.540 --> 0:07:28.940 process that consistently created a smooth textured chocolate and made 0:07:28.980 --> 0:07:35.290 chocolate more affordable to mass-produce. By the early 1900s, Nestle, Hershey, Cadbury, 0:07:35.550 --> 0:07:38.130 and other big names in chocolate were churning out candy 0:07:38.150 --> 0:07:41.050 for the masses. And the process hasn't changed a lot 0:07:41.090 --> 0:07:45.060 since then. Which isn't to say it's not complicated. It is. 0:07:45.660 --> 0:07:47.920 And it does vary depending on the company and how 0:07:47.960 --> 0:07:50.720 the chocolate will be used. But it always starts with 0:07:50.740 --> 0:07:54.600 those beans. Some companies rely on a single source for 0:07:54.640 --> 0:07:56.940 their beans or only buy them from a certain region. 0:07:57.620 --> 0:08:00.240 Experts compare the cacao bean to a wine grape. There 0:08:00.260 --> 0:08:03.300 can be huge differences between beans depending on where they're 0:08:03.320 --> 0:08:06.530 grown and how they're treated. Big companies tend to use 0:08:06.550 --> 0:08:11.050 proprietary blends to create a consistent flavor. The first step 0:08:11.070 --> 0:08:13.750 when the beans show up at the chocolate factory is roasting, 0:08:13.990 --> 0:08:17.010 which removes bitterness, mellows the beans by evaporating some of 0:08:17.050 --> 0:08:21.260 the acids that they contain, and develops desired flavors. A 0:08:21.320 --> 0:08:23.520 part of this is through a chemical reaction called the 0:08:23.560 --> 0:08:27.180 Maillard reaction, which is also responsible for the roasty flavors 0:08:27.200 --> 0:08:30.590 in a lot of other foods, too. The Maillard reaction 0:08:30.650 --> 0:08:33.550 happens when sugars and amino acids react with each other 0:08:33.670 --> 0:08:36.359 in the presence of heat. And in cacao beans, it 0:08:36.520 --> 0:08:41.839 helps create the distinctive flavor and smell of chocolate. After roasting, 0:08:41.980 --> 0:08:44.220 the beans are then winnowed from their hulls and crushed 0:08:44.260 --> 0:08:48.440 into nibs, little kernels of bean. Those kernels can be 0:08:48.480 --> 0:08:52.260 sold as is or ground into paste, sometimes called chocolate liquor, 0:08:52.660 --> 0:08:56.830 for further processing. The next step is grinding, which is 0:08:56.870 --> 0:09:00.000 done by a machine called a mélangeur, which has huge, 0:09:00.179 --> 0:09:03.559 traditionally granite rollers that mash the cacao nibs into a 0:09:03.600 --> 0:09:07.540 paste called mass. The mass goes into a powerful press, 0:09:07.740 --> 0:09:11.280 which splits the cacao into its two components, powder and butter. 0:09:11.300 --> 0:09:13.610 If the powder is going to be used to make 0:09:13.660 --> 0:09:17.869 drinking chocolate or cocoa powder, it's pulverized very fine. If 0:09:17.890 --> 0:09:20.809 the confectioner is making solid chocolate, workers may make it 0:09:20.929 --> 0:09:23.210 straight from the mass or start with cocoa powder and 0:09:23.290 --> 0:09:26.470 add some cocoa butter back in. Good chocolate will use 0:09:26.550 --> 0:09:29.930 mostly or all cocoa butter as its fat. Cheaper chocolate 0:09:29.950 --> 0:09:33.150 will use other vegetable oils, too. Now's the time that 0:09:33.170 --> 0:09:36.920 they'll also add in sugar and any emulsifiers and other flavorings. 0:09:38.140 --> 0:09:41.360 The next step is the aforementioned conching, so named because 0:09:41.400 --> 0:09:44.940 of the shell-shaped cylindrical grinding machine that Lindt created for 0:09:44.960 --> 0:09:48.569 the process. The machines that companies use for conching these 0:09:48.610 --> 0:09:52.310 days are proprietary, guarded secrets, but they're all designed to 0:09:52.330 --> 0:09:55.679 do a few of the same things— A continual grinding 0:09:55.820 --> 0:09:59.189 action evenly distributes the cocoa butter within the chocolate mass, 0:09:59.650 --> 0:10:04.480 creating a smoother mixture. The friction polishes the cocoa particles 0:10:04.660 --> 0:10:07.979 and makes them smoother. It also generates heat in the 0:10:08.020 --> 0:10:12.439 cocoa mass, releasing volatile oils and flavor compounds. If the 0:10:12.460 --> 0:10:14.860 mass contains milk powder, which is often the case when 0:10:14.880 --> 0:10:19.980 making milk chocolate, heat will also encourage the Maillard reaction. Finally, 0:10:20.240 --> 0:10:23.610 the rotation introduces air into the mass, removing more acids 0:10:23.710 --> 0:10:27.570 and bitter compounds. The result is a smooth, even mixture 0:10:27.630 --> 0:10:31.730 of liquid chocolate that's easy to pour into molds. But 0:10:31.750 --> 0:10:35.189 before it hits the molds, the chocolate is tempered. This 0:10:35.230 --> 0:10:37.630 is a process of heating and cooling the chocolate to 0:10:37.870 --> 0:10:40.980 basically mitigate the size and shape of the cocoa butter 0:10:41.050 --> 0:10:45.380 crystals within it. Yes, cocoa butter molecules stack themselves in 0:10:45.460 --> 0:10:49.570 crystal structures. The issue is that they'll form different structures 0:10:49.650 --> 0:10:52.309 depending on the temperatures and length of time at which 0:10:52.330 --> 0:10:55.489 they're allowed to solidify. Too cold and quick, and the 0:10:55.530 --> 0:10:58.870 resulting chocolate will be soft, and after it's finished, some 0:10:58.990 --> 0:11:02.130 fats may bloom to the surface, making it feel oily 0:11:02.230 --> 0:11:05.860 and crumbly. A warmer, but still too quickly, and the 0:11:05.880 --> 0:11:09.980 chocolate will be firmer, but still bloom fats. The magic 0:11:10.040 --> 0:11:12.080 temperature is right around 93 degrees Fahrenheit, or 34 Celsius. 0:11:14.660 --> 0:11:17.700 And letting it cool very slowly will produce the correct 0:11:17.800 --> 0:11:20.620 type of cocoa butter crystals that results in a chocolate 0:11:20.710 --> 0:11:23.290 so hard that it snaps when you break it, with 0:11:23.330 --> 0:11:26.750 a nice shine to the surface and a smooth, melt-in-your-mouth texture. 0:11:27.990 --> 0:11:30.990 The tempering process can require multiple steps of heating and 0:11:31.070 --> 0:11:34.189 cooling to get most of the crystals on the same page. 0:11:35.230 --> 0:11:37.750 In factories, there are machines that do it automatically to 0:11:37.830 --> 0:11:40.630 take out the possibility of error. So if you've ever 0:11:40.670 --> 0:11:42.930 had trouble with it in your own kitchen, you're doing 0:11:42.960 --> 0:11:48.300 just fine. Although cacao is originally from Mesoamerica, today most 0:11:48.340 --> 0:11:51.700 of the world's supply comes from West Africa, namely Ghana 0:11:51.800 --> 0:11:56.359 and the Ivory Coast. As of 2025, about 69% of 0:11:56.400 --> 0:11:59.870 cacao was produced in Africa, but only 23% of it 0:11:59.950 --> 0:12:05.910 is processed there. Europe leads with about 36% of cacao processing. Usually, 0:12:05.929 --> 0:12:09.270 cacao is grown on small family-owned farms of less than 0:12:09.270 --> 0:12:13.780 10 acres or 4 hectares. Mass agricultural production just isn't 0:12:13.880 --> 0:12:18.020 possible because cacao farming is so intensive. Again, the pods 0:12:18.059 --> 0:12:21.560 are selected and harvested by hand. There's no other way 0:12:21.600 --> 0:12:24.400 to remove them without damaging the bud from which additional 0:12:24.450 --> 0:12:29.510 pods will grow. Unfortunately, as global demand for chocolate has increased, 0:12:29.809 --> 0:12:33.870 the labor issues surrounding it haven't magically gone away. For 0:12:33.890 --> 0:12:36.510 the hundreds of billions of dollars the industry is worth, 0:12:36.890 --> 0:12:40.310 many cacao farmers live in poverty. And child labor and 0:12:40.370 --> 0:12:44.949 even trafficking and enslaved labor are still serious issues. Demand 0:12:44.970 --> 0:12:47.860 for cacao has also meant destruction of rainforest to plant 0:12:47.900 --> 0:12:51.420 more of it. To help as a consumer, look for 0:12:51.440 --> 0:12:55.179 the fair trademark on chocolate products. These companies have agreed 0:12:55.220 --> 0:12:58.350 to pay an above-market price for cacao to help the farmers. 0:12:58.850 --> 0:13:01.870 And they support international programs to help communities where cacao 0:13:01.929 --> 0:13:05.920 is grown. It's not a perfect system, though. If you 0:13:05.990 --> 0:13:08.850 want to dig a little deeper, look up resources like 0:13:08.970 --> 0:13:12.189 the Chocolate Scorecard and the Food is Power Chocolate List 0:13:12.590 --> 0:13:16.380 to learn how different companies shape up. Treats are nice, 0:13:16.770 --> 0:13:19.400 and buying them from companies that care about their workers 0:13:19.840 --> 0:13:26.920 is even better. Today's episode is based on the article, 0:13:27.100 --> 0:13:30.310 How That Creamy Chocolate is Made, on HowStuffWorks.com, written by 0:13:30.370 --> 0:13:33.490 Shanna Friedman and Aliyah Hoyt. BrainStuff is a production of 0:13:33.550 --> 0:13:36.870 iHeart Podcasts in partnership with HowStuffWorks.com and is produced by 0:13:36.910 --> 0:13:40.440 Tyler Klang. For more shows from iHeart Podcasts, visit the 0:13:40.540 --> 0:13:43.700 iHeart Radio app, Apple Podcasts, or wherever you listen to 0:13:43.720 --> 0:13:44.559 your favorite shows.