The Tech of Coffee

I thought we would explore the technology around coffee. And you might be thinking, hey, Jonathan, it sounds like you're just making episodes out of stuff that you can see from your chair right there in your home office. And to you, I reply, s, don't you worry a little hit about that. It's none of your concern, So let's talk about coffee now. I also know that episodes like this one and My Lawnmower one are going into a lot of history and culture type stuff, not strictly the technology.

But I always feel like an understanding of technology, a real understanding of it, requires that, you know, we also explore the greater context, Like we could just talk about how the technology works at all and how someone came up with an idea and maybe someone else improved on that idea. But I think that has limited value unless you explore why were people thinking about this in the first place, and what the world was like before and

then after that technology. Also, I've recorded more than episodes of tech stuff, so changing things up keeps it fresh from me, and then I don't burn out. But hey, you folks are my listeners. If you like how these episodes play out with a deeper dive into the context around tech, let me know. Now. If you hate them, you can also let me know, but do it nicely, because yeah, it's just me doing all the researching and

writing and recording of these shows. Now. Coffee is one of those subjects that I find particularly fascinating because there are countless people obsessed with it, and yet details about its origin and evolution in society are somewhat muddled. It's amazing that we've got this huge industry around coffee, but we don't have a lot of historical records to refer to when it comes time to documenting everything about it.

Maybe people were just too jittery to write anything down, So in the absence of facts, people will fill up the gap with speculation. That's just a general rule of thumb. You didn't think this was gonna be an episode about critical thinking, but bam, right out of the gate, I'm hitting you with it. Now, if you google history of coffee or origins of coffee, you're gonna find results, like a lot of them. I mean like million of them.

I know because I did it. And if you spend enough time skimming through a few of these different results, you're probably going to find several very different explanations about the history of coffee. Some might start as early as the sixth century of the Common Era, others might flip ahead of millennia or so. So this tells us that we should probably not put too much stock into any one narrative about coffee. It maybe that none of these accounts are correct, or maybe they all are, in some

way or another at least partly correct. So we shall proceed with caution. First, let's talk about coffee the plant to understand what it is. Now, maybe you've never seen one in person. By the way, if you ever find yourself on the Big Island of Hawaii, you can go to the Kona region and tour one or more coffee plantations. I've done the tour of Greenwell Farms and it was super nifty, And no, I don't have any connection to

that farm or that brand of coffee. I just liked the people that I talked to there, and I found the tour really fascinating, and the various animals roaming around the farm were super cool as well. Coffee plants don't get particularly huge. They typically fall somewhere in the range from shrub to medium sized tree. Cultivators typically trim the branches back to keep them manageable, especially if you're cultivating

them in rows. You want those rows to be nice and neat, and it allows you to fit more plants per area of land. They have glossy green leaves and these plants sprout small white flowers in the springtime, followed by berries or the coffee cherry. And these are about half an inch in length or about one point three centimeters, And these are the coffee cherries. Inside each cherry are two green seeds. These are the actual coffee beans, which

aren't really beans at all. Their seeds. Inside each cherry are two green seeds, and these are the coffee beans, and they're not really beans at all. They are seeds and they only become brown after you roast them, and that comes much, much, much later. The fruit of the coffee cherry is sweet. You can actually chomp on these if you want, but there's not a lot of pulp

to these fruits. A coffee cherry is mostly skin and the two seeds, and then you've got a little bit of fruity pulp called mucilage on the exterior of the seeds. The seeds are super hard, so you don't really chew on the seeds. It would really hurt your teeth. And it takes a lot of work to eat the tiny amount of fruit that's on a coffee cherries, more work than what it's worth, which is why you don't go to the grocery store and load up on coffee cherries

as a sort of pick me up fruit snack. But what's the history of humans cultivating coffee for its caffeinated kick. That was a lot of alliteration that I did not initially intend. Well, there's one tale that is pretty widespread to the point that I think we can really consider it folklore. Now this doesn't necessarily mean it's not true. It just means that, you know, it's a story that's been widely passed on through oral tradition, giving lots of

opportunities for that story to change in little ways. I think it's probably a little fanciful, but again I don't know for sure. But the story goes that there was a shepherd in Ethiopia who was tending to a trip of goats. And yes, I did just google what to call a group of goats a trip? I guess. I guess the word heard would have been fine, but I

wanted to get, you know, more specific. And besides, a trip of goats seems fitting, as this shepherd's goats were nibbling on some little shrub plants and then they were tripping all over the place. Man, those goats were tripping, or rather they were jumping, skipping and leaping, one might almost say dancing. And the shepherd, someone who clearly had a lot of time on their hands, decided, what the heck,

I'm going to see what this is about. And so the shepherd then took some of the berries growing on these plants and showed on them, and then felt a surge of energy. So if you ever wondered whose job it was to test the various types of fruits and mushrooms and everything else to make sure that it was safe to eat. I'm guessing was folks like our shepherd in this story. Here. Also funny side note, the coffee shop I go to all the time has a name

that references this folk tale. The coffee shop is called Dancing Goats. Now when this story happened, if it happened at all, is also a matter of debate, but generally we're looking at around mid ninth century of the Common Era, or around eight d fifty a d if you prefer. But as I say, there's not really any evidence that it definitively happened. And heck, I'm not sure anyone would even think to record that kind of event. I mean, dear Diary, I saw my goats eat some berries and

then they went totally bonkers. So I ate some berries, and I too went bonkers. Tomorrow I opened a Starbucks. Like that just didn't happen. So there are some facts that at least make the story or some variant of it possibly true, And the big one is that the coffee plant grows naturally in Ethiopia in a region called Kafa, So did coffee get its name from kafa, or did kafa get its name from coffee? Heck, if I know, there are other words that sound a lot like coffee

that are directly associated with coffee. So this is one of those that I think I will leave to the linguistic experts. Now. It's possible that some people had discovered the properties of this odd little fruit long before the ninth century. But the first written account about coffee that I could find evidence of came from a philosopher named Rozis from Persia who lived right around the time that the Shepherd's story might have happened. Rozis wrote of a

medicine used by the peoples of Ethiopia. It was a drink made from the fruit of the coffee plant, but from the description it didn't sound like coffee as in the drink that we enjoy these days. Yemen is a possible origin point for coffee, the drink as we know it. Sufi monks and Yemen brought coffee cherries from Ethiopia, and then they cultivated the plants, and Yemen it grew just fine. And Yemen as well. The monks made a sort of tea from the coffee plants. Leaves to help them stay

awake longer and get more prey and done. Now, this would have been around the fourteen hundreds, and it's possible that these monks gradually developed the process of roasting and grinding coffee beans to make their stay awake juice. In

the fifteen hundreds, the Turks came a colon. The Ottoman Empire was an expansion mode, and while it never extended all the way down to Ethiopia, it did get quite the foothold in the Arabian Peninsula, which is where the Turks first encountered coffee, and they really liked it like a lot, and they called it covey, which in Turkish

meant the wine of Arabia. The drink made from roasted coffee beans soon found its way throughout the Ottoman Empire, which was enormous and spanned parts of Europe and North Africa at this point, and growing coffee outside of places like Yemen and Ethiopia proved to be challenging. In part, that was because the plants thrived in very warm, like tropical style climates and temperate Europe was just a bad match.

It was too cold. But the merchants selling coffee also saw a threat to their trade if people were able to grow the coffee plants in any old place, and so they would frequently boil or otherwise alter the beans before selling them, so that those beans would be infertile. If you were to plant them, nothing would grow from them, and then they would ship those off to be sold

in places like Europe. It wouldn't be until the seventeen hundreds before someone, that being the Dutch, was able to get hold of viable coffee beans and find a place to grow them outside of the general areas of Yemen in Ethiopia. But we'll get back to that. By the mid sixteenth century, coffee shops were opening up in Constantinople. Now you can't go back to Constantinople, so if you have a dating Constantinople, she'll be waiting in his stan bull.

I have no idea if it was common for a coffee house to open up right across the street from another coffee house, or if that's just something we do here now. Over in Western Europe, it said that some high ranking Catholic priests resisted the spread of coffee, declaring it to be a devil's brew. I mean it kept you awake, It gave you energy. It clearly was unnatural. But the Pope apparently like the stuff and said, Noah,

this is fine. It's fine. And so coffee spread throughout the Christian world as well over in England, where they had already had a little tiff with the Catholic Church, it was now the Anglican Church in control. Over in England,

they got their first coffee shop by sixteen fifty. That was just a century after the earliest ones we know about, opening up in Constantinople, which really surprised me because frequently, when it comes to trends in the Middle Ages and Renaissance, England typically is a latecomer because it was, you know, separate. It was not part of the mainland of Europe. Still isn't as far as I know. I haven't looked at

a map recently. But in this case, the Brits got their coffee before the French started opening up their own coffee shops. Coffee even made its way over to the colonies in North America, with a coffee shop opening up in what would become the city of Boston in sixteen

seventy six. Okay, so the Dutch I mentioned that they got some viable coffee beans essentially smuggled them out of Arabia, but they had to find a good place to grow coffee, and that turned out to be Indonesia, specifically the colony of Java, which is why we sometimes referred to coffee as Java. The Dutch secured their coffee beans through trade with a port city in Yemen, and that port city's

name was Mocha. That's how we got Mocha Java. Starting in the early eighteenth century, from their colonialism, would spread coffee to other parts of the world, such as Sumatra that's an Indonesian island west of Java, Central America, South America, the Caribbean, and Hawaii. And before you can throw some coffee scenes or beans into a grinder and prep your morning cup of joe, there are a lot of stuffs

that have to take place between growing it and brewing it. First, someone's got to harvest those cherries from the coffee plants. And in fact, there is a whole element to this story that I'm not going to dive into, but it does involve some pretty terrible conditions for workers in various

parts of the world. There's a lot of exploitation going on whenever you're talking about mass farming in places like Central America or South America, or Indonesia or Africa, you've got a lot of opportunities for companies to do things that are not necessarily the best for the employees. But that's a matter for another episode. On smaller farms, harvesting might be done by hand, possibly with some hand tools, but on the big farms, heavy machinery is frequently used.

While some coffee farms use pickers to harvest cherries by hand, like just with their hands alone, others rely on some of those simple hand tools. I was talking about one tool I've seen for harvesting coffee really surprised me. I hadn't really seen anything like it before. Or kind of looks like a pair of tongs, and that there are two rods that extend out from a plastic handle, and the handle actually has motors in it that vibrate and

rotate those fiberglass rods. So while you're operating this harvesting device, those rods are spinning and vibrating very quickly. To harvest the coffee cherries, first, you put a tarp down to catch all the cherries that are going to fall, which is pretty much the same thing you would be doing if you were harvesting everything just using your hands alone. Then you would position the rods on either side of

a branch that happens step berries on it. You'd squeeze the handle so that the two rods come together and and touch the branch on either side, thus transmitting vibrations to the branch, and then you move the tongs down along the length of the branch to shake the berries free. It's still a lot of work because you have to move from branch to branch, but it's more efficient than

doing it all with just your fingers. Now, this is a fairly simple device with electric motors in the handle that draw power from a battery pack, so I'm not going to go into deep detail. There's not a whole lot of of advanced tech there. It's just the idea of creative vibrating motor that transmits vibrations to a rod. Those rods transmit the vibrations to a branch you knock

the cherries loose. Another tool I've seen for this kind of harvesting looks almost like a weed whacker or a weed eater, except instead of having a rotating blade or a rotating wire. At the end of the device, you actually have what looks like almost like a fiberglass rake um or a fork. In fact, it does look like an enormous gas powered fork, and the motor when you turn it on, makes the tines of that fork vibrate. So again, you would just use this device to grip

several branches of a coffee planet. Once you give some gas to the motor, it causes the times to shake, and it shakes the cherries free from the coffee plant, and presumably you catch those on a tarp. But for really big farms, there are some massive machines that farmers used to harvest coffee. When we come back, i'll explain more, but first let's take a quick coffee break, all right. So for smaller coffee farms, or maybe ones that are on like really uneven terrain, you might not be able

to use big machines. They might just not be able to maneuver through those. But for coffee plantations that are really huge, particularly ones that have coffee plants and neat rows and fairly level ground, you get a lot of options.

One harvester I've seen is a big device that's actually stationary when it's an operation, and it looks kind of like a big metal wagon with an archimedean screw inside of it and a shoot like protrusion at one end, which is where the coffee cherries will come shooting out and into another container. So you would tow this big thing to the end of like a pair of rows of coffee plants that stretch pretty far back, and between

the rows you lay down a tarp. This tarp will become a sort of conveyor belt for the harvester, and workers would go down the rows of coffee plants and use pruning shears to trim back branches that have berries on them. All of these branches with berries on them fall down to the tarp below, and once that's done, you feed the tarp into essentially a roller in the harvester, which will start to pull the tarp into the machine.

Uh And they typically also has some sort of hinged metal frame that you can use a sort of a ramp, so that way the tarp is going up at a at a gentler angle. It's not going up so steep that everything falls off the tarp. So the machine starts pulling the tarp toward it and everything on the tarp gets pulled along with it and dumped into a chamber. And in that chamber there is that Archimedean screw at the bottom. And if you don't know what that is,

is a cylindrical drum with a helical blade. It's the type of thing that Archimedes used to draw water from areas of low elevation to high elevation, and in this case, it's used to transport the coffee cherries up toward another set of devices attached to this machine. So the branches and berries and leaves and all go into this chamber with the turning our comedian screw. The rotational motion separates the cherries from the branches, and the cherries effectively roll

up the screw because of that rotation. This is a little hard to explain an audio, so I recommend you check out the videos of watching an archimedian screw in action. You'll see how it all works. And the cherries and maybe some bits of leaves and twigs hit a shaking grid at the top of that archimedian screw. This shaking grid acts like a filter. It allows the cherries to pass through the filter. Everything else doesn't or at least

most of everything else doesn't. And then the cherries ride a second conveyor belt that has you know, these little ridges to keep the cherries from rolling back down, And this belt carries the cherries up a shoot and then they come out the other end and fall into whatever

containment vessel you have to collect all those coffee cherries. Uh, you could end up with something that looks like essentially a dumpster full of coffee cherries, and the branches and leaves they get left behind are are chopped out quite a bit. They eventually exit the machine through an exhaust, kind of like the way a lawnmower has one of

those little side exhaust ports where cut grass flies out. Now, this sort of device can harvest a lot of cherries, but it does require a ton of manual pruning work at the top end of it. There are some other harvesters that take the cherries right off the plants without needing to cut the branches onto a tarp first, and they look pretty funky. Now, there are a lot of variations on this next type of harvester, but they do

share a few things in common. And the easiest way I can think of to describe this is imagine a mechanical automated car wash. You know, you drive your car into the bay of this car wash, and then once the car washes operating, these big machines will rotate giant brushes that come up against your car and scrub all

that road grime off your vehicle and then you drive out. Well, imagine that you've got a car wash, but the car wash itself is on wheels, So instead of the cars driving into a stationary bay, you could have a line of cars that are you know, bumper to bumper in a line, and you have this wheeled car wash go down the line of parked cars, and the car wash is the thing that moves. Well, that's kind of what these harvester things are. Acceptance to have a car wash. Obviously,

they are harvesting coffee cherries off of plants. So you've got this big machine that has a space where a tree can pass through the middle of this machine. The machine is on wheels, so it can move because you know, these are coffee plants. They're not ents from Middle Earth, so they don't walk around on their own no matter how much caffeine is in them. Some of these machines are things that you have to tow behind a tractor, But some of them have a tractor like system built

into the actual machine. So some of them have their own engine and motor that allows you to drive the harvester, whereas others are a separate piece of machinery that hooks onto the back of a tractor. I've seen both versions, but either way, a driver manipulates this machine, so it moves down a line of coffee plants in order to harvest the cherries. So how is that harvesting actually working well?

On the inside where the trees are passing through, You've got poles with fiberglass rods on either side of where the coffee plants passed through. So it kind of looks like one of those round brushes where you've got the

bristles on all sides of the round brush. It looks like a pair of those, except not quite as thick, and you've got a bunch of fiberglass rods instead of bristles, and instead of big rotating brushes from a car wash, you've got these things and they do rotate, and the fiberglass rods vibrate as they're rotating, and it's this motion that shakes loose the coffee cherries as the plants pass

through the middle of the machine. At the bottom of this are some hinged panels that can allow a tree trunk to pass through in one direction, but the panels locked from being able to go in the opposite direction. So they're hinged in a way where uh they swing open to allow a tree trunk to pass through, but when they close, they can't go back the other way. So once you head down a row of coffee plants,

you're kind of committed. The hinged panels catch stuff that's falling down from the coffee plants that gets shaken loose, and all that material, including cherries, toigs, leaves, bugs, moves towards a pair of conveyor belt, one on either side of the inner part of the machine. These conveyor belts move everything up to either a containment chamber or out of to a shoot where they get put into a separate trailer that's being hauled behind a different tractor, perhaps

one row over. I've seen both um, but some of these things are kind of an all in one machine where they can do all the driving, the harvesting and collecting of coffee cherries by themselves. And don't need any additional equipment or other people operating that equipment. Some of them are used in concert with other heavy duty machinery. There are a lot of videos online if you want to see these coffee harvesters in action. It might be a lot more helpful rather than trying to imagine my

poorly constructed word picture. Uh. The the machines are pretty impressive, and they're actually based off older harvesters that have been used for stuff like blueberry farms. Now, before I did this podcast, I had never seen anything like this. Being the city boy I am, and also I mean I have actually done some very very minor work on a farm. Uh it's barely worth mentioning. But it was a much smaller operation, not something that would have this big equipment.

So I've never seen anything like this. It was really cool to learn about it. One of the videos I watched for this episode had a coffee farmer named James Chemo Falconer, and he talked about the efficiency of these types of harvesting machines. Now, according to Falconer, a skilled coffee picker would be able to harvest around two hundred

pounds of coffee cherries in a day. One of these harvesters could actually harvest forty thousand pounds of cherries in around six hours, so it is phenomenally efficient compared to manual labor. Now keep in mind we are still talking about coffee cherries here Again. According to Falconer, there's about a five to one ratio in weight of cherries to weight of green coffee beans for natural coffee. Some varieties of coffee might have cherries with slightly more or less pulp.

That would change the ratio a bit. But if you harvest forty thousand pounds of coffee cherries, that doesn't mean you've got forty pounds of coffee beans. It's like a fifth of that. Now, the harvested cherries have to be washed to remove dirt, stems and that kind of stuff. There's typically an early sorting process to help separate out unsuitable coffee cherries from the good stuff. One way that you can do that is dumping all the cherries into giant vats of water. Cherries that float to the top

aren't ripe. They can be skimmed off and they can be removed and then punished. I'm kidding, they're not punished, but they are turned into fertilizer, typically so that you can use those to help fertilize the ground for future coffee plants. Now, what happens next is dependent upon the post harvest process for that particular coffee farm or plantation.

Dry regions might use natural processed coffee, which involves leaving the seeds inside the coffee cherry and allowing the whole thing to dry out, which takes about four weeks and it requires lots of supervision to make sure that mold doesn't form on those coffee cherries. And after drying, workers put cherries into a huling machine. Uh. There are a lot of different versions of this. One of them is just essentially a big vibrating tray. You put the coffee

cherries into this vibrating tray. It often has a rough bottom, and the vigorous shaking of that tray using an electric motor to to shake this thing ends up rubbing and shaking the cherry so that the dried skin and dried fruit, and the parchment on the seeds itself all gets rubbed off,

which really means that those those seeds, those coffee beans. Now, the green coffee beans just need to be polished before they're sent off to roasters because you've already done all the work of removing everything else that's around the bean. But another climates, different post harvesting methods work better. So you've got stuff like your honey processed coffee or your wet hull process, which is mostly used in Indonesia, and

you've got your washed coffee processing. Now there are several things that differentiate these processes, and even plantations that use the same general process will have their own way of executing that process. So there's no I can't give you a universal here's how it works. I can give you some generalities with each. So with honey processing, the cherries are skinned right away after harvest, but the sticky coating

on the seeds that mucilage. That mucilage is allowed to stay on the seeds while they go to areas to be dried out. The washed process involves pulping the seeds not long after harvest. You allow the seeds to ferment a bit like overnight, and then you wash the musilage off before you allow the coffee to dry, and that coffee will dry faster because it doesn't have that insulation around it. But that also means that it's not in contact with the fruit for as long, and that will

change the flavor profile. In the case of natural processing, honey processing, and washed processing, the goal is to get the moisture level of the seeds down to around eleven before you move on to hulling the seeds, to get that thin layer of parchment off the coffee seeds before

you can send them off to roasters. Now, the wet hull process of Indonesia is a little bit different because of the high humidity levels in Indonesia, it would be really hard to dry seeds down to eleven water content on their own, even with the washed process method, So instead they pulp the cherries so that you get the seeds the coffee beans, and then they dry those coffee beans until the water content is around thirty percent or so remember the other ones are, and then they feed

those to a hauling machine to remove the parchment layer around those seeds at that point, whereupon they dry more efficiently. In the human climate, the other processes I mentioned leave the parchment on the seeds until after the drying process

is done. The parchment helps protect the seeds against stuff like disease and mold, but in the really humid climates, Even that thin layer of parchment slows down the drying process, so in order to get the seeds dried and to market while they're still good, they have to remove the parchment. In places like Indonesia, pulping and hauling machines can be vibrating trays like the one I mentioned for natural processing,

or they can involve feeding the cherries or seeds. In the case of if you're just removing the parchment into a feeding hopper, and at the bottom of the feeding hopper is typically a rotating drum that's got little nubby protrusions on it, and as the drum rotates, this agitation UH squeezes seeds out of the cherries, and it can also remove parchment from the seeds if you've calibrated the

machine to do so. But it's that rotational force that is UH kind of separating the cherries out from the seeds infect It kind of squeezes them out and the chair the seeds go one way, and the cherries, the pulp and the skin go the other way. So you will get one shoot where green coffee beans will slide down, and then on the back you'll just have this mass of pulp shot out the back of the the machine,

which again is used often for fertilizer. The holed coffee then has to be sorted by size, and a typical sizing machine has a series of meshed trays stacked one on top of the other in a vibrating device, and the holes in the mesh decrease in size as you go down the stack vertically, so larger seeds will be caught by one of the upper trays because the seeds will be too large to pass any further down in

the link of of meshes. Uh, the smaller seeds will eventually collect in the bottom trays because they'll pass through the larger holes on the upper ones. Then the coffee can be graded based on coffee bean size. The best coffee beans, by the way, are not necessarily the biggest ones, nor are they the smallest. It's typically the just right the goldilocks zone. Those seeds also have to be examined

to make sure they are the right quality. They have to be looked at to make sure they're the good color. This can be done by I but when you're looking at really big operations, that's not practical. So we've got some high tech to do this too. There are advanced machines that use l e ed s and high resolution cameras and imaging software to examine seed color and consistency, and that makes it possible to sort large quantities of

seeds and remove any that don't meet specifications. So I always think of the Willy Wonka and the Chocolate factory scene with the golden eggs. You've got these machines that are looking at seed by seed very very very fast, and if the color and the consistency matches the specifications that the machines software has set to, then the beans are allowed to continue on their path. If not, they get the boot. They are the proverbial bad eggs in

this case. Other machines sort the beans by density using vibration and air. So, in other words, you've got a big stack of beans, you put them in this machine. The machine shakes the beans, that uses some air to blow against the beans. The heavier beans will be closer to the bottom of this machine. They'll be heavy enough and dense enough to make their way to the bottom. The very light beans will be more towards the top of the machine because they'll be blown by the air

and they will be pushed up from all the heavier beans. Now, you want to do this because sometimes those lighter beans are actually representative of beans that have been you know, munched on by insects and stuff. Those are not the best. So it's another way of sorting beans out very quickly for quality control. Now, what I think is really cool about a lot of these devices is apart from the one that tends to use like high resolution cameras to

look at bean color. Now, what I like about a lot of these devices is that a lot of them use a pretty simple mechanical approach to help sort out all these beans. I just think it's a neat and pretty elegant way of doing things. All this takes place

before roasting. The coffee roasters take incoming green coffee beans and, depending on the flavor qualities of the bean, which in turn are determined by stuff like where in the world it was grown, what sort of post harvest processing to go through that kind of thing, the roasters then take that, they take that flavor and they determine what sort of roast they should follow for those particular beans. The beans are put into roasting machines, which look a lot like

clothes dryers. A lot of these, especially for the larger roasters, are gas power. They actually use natural gas for a heating element. So a typical roaster has a hopper feeder at the top that's where you pour the green coffee beans in. These flow into a barrel that is inside the roaster. The barrel can rotate, and the barrel has burners on the outside of it, so inside the machine, but outside the container of the barrel are these burners.

They heat up the air and the barrel itself, and that allows these beans to get a lot of heat directed at them in a very short amount of time. And you use a combination of temperature and time in order to roast the coffee beans. They're constantly being circulated so that each bean is getting evenly heated. And typically there's a way to remove beans from the middle of this process while it's still going, so you can check on progress. Uh. There's frequently something that's called like a

sample spoon. This is a little container that actually can extend into the barrel as it's an operation, but there's a handle on the outside of the machine that you can grab. You can pull the sample spoon out, check the beans that are in the process of roasting and reinsert the sample spoon to put them back into the barrel, and you know, use that to check to make sure that you're not going too far with your roasting process.

After roasting, the roasters will essentially open a flap to the barrel to let the roasted beans pour out of the barrel into a cooling tray. Then the roasters will either stir the beans or typically a lot of these cooling trays have a mechanical stir that will just do rotations through the beans and mix them up. That allows the beans to cool and stop the roasting process from

going on much longer after they've already emerged from the roaster. Now, the length of time spending those chambers, along with what temperature you set it to, that determines the level of the roast, and the flavors can change in that time as well. So a light roast coffee uses beans that have been in a roaster for much less time than a dark roast coffee, and light roasts tend to be a little more floral. Dark roasts tend to have more chocolate e or caramel flavors, but also roasting the longer

eu roast. The more you typically reduce the amount of caffeine that's in the the coffee bean, the caffeine gets kind of roasted out gradually. There's still some there, but less so. While an espresso has a very strong flavor, it can actually have much less caffeine per volume than a simple light roast coffee. Though this is also dependent upon the type of bean that was used at the very beginning of the process, so it gets a little

more complicated than that. There are some great videos on YouTube of master coffee roasters describing the process they use, which frequently needs to have some flexibility built into them. Figuring out the perfect temperature and the perfect timing to get the kind of roast you want is kind of a matter of science and art. It's fascinating stuff. Now, when we come back, I'll talk about the evolution of

the coffee maker. One thing I did not cover in the previous section is how companies make decaffeinated coffee and coffee beans half caffeine in them. How do you decaffeinated Well, there's a couple of different methods, but generally the process involves leaching the caffeine out of the green coffee beans. Using some form of chemicals or an activated charcoal filter to bind with the caffeine, and then continuing to soak green coffee beans so that some of that delicious flavored

juice goes back into the bean. In fact, in many of these processes, the first batch of green coffee beans is either a loss. You just throw them out after you've soaked them in hot water, or you have to set them aside because it's not just the caffeine that leeches out. There's also a lot of those oils that make up the aromatics and flavor of the coffee bean.

So if you wanted to decaffeine eate a batch of coffee, you would put your first group of green coffee beans in a vat of hot water, and then the water becomes saturated with caffeine and these oils. Then you would use chemicals or a charcoal filter to bind with that caffeine and remove the caffeine from the mixture, and then you could remove the green beans from that mixture, and then you add more green coffee beans, the ones that

haven't been processed yet into the vat. Now the hot water is already saturated with the oils from the first batch of coffee beans. So the second batch of green coffee beans keeps the flavors and aromatics for the most part, but the caffeine still leaches out. Then you use that same chemical process to bind with the caffeine molecules and

remove the caffeine from the mixture. And at the very end of this process, after you've done batch after batch after batch of the green coffee beans, maybe then you go ahead and you add back that first batch of coffee beans to stew in the juices. As it were, These are the coffee beans that were sapped of not just their caffeine but all their coffee goodness, and you

let them sort of reabsorb those chemicals minus the caffeine. Obviously, now it's a little more complicated than that, and as I mentioned, there are a few different approaches to this, but I still need to talk about coffee machines, so let's move on. Gosh darn it. So to brew coffee, you grind up the beans to create more surface area for the beans to make contact with hot water. That allows more oils to transfer to that hot water, and

thus the drink we call coffee is made. And there are many different sizes of grinds of coffee, ranging from course to extra fine, and they're they're good for different types of coffee preparations. For example, a very coarse grind is recommended for cold brew coffee or French press coffee, a meat grind is good for your standard automatic drip coffee machines, and an extra fine grind is really good

for Turkish coffee pots. Typically, you want to filter out the coffee grounds from the water so that the stuff you've brewed doesn't have coffee grounds in it, unless you're making Turkish coffee. So you might pour boiling hot water over coffee grounds that are in some sort of filter.

That's the classic pour over coffee, or, as is the case with most coffee machines, you have a filter or perforated surface that keeps the grounds from passing through and the coffee can move on into a caraft or pot or pitcher, while the coffee drink is able to you know, flow freely and everything. One of the earliest modern applications for coffee making is the humble percolator. Joseph Henrie Marie Lawrence, a metal worker in Paris, invented such a device in

eighteen nineteen. The ideas atty simple. You've got a pot complete with a spout. You know, it doesn't look that different from a kettle. UM. This sits on top of a source of heat, like an open flame or an electric stovetop. You fill the bottom part of this pot with water. You've got a vertical tube that extends up from the bottom of the pot to the top. Sometimes this is actually a separate piece that you insert into

the pot after you've already filled it with water. UM. That means that the water in the tube is at the same level as the water level of the pot. And at the top end of this tube is a perforated basket of some sort. That's where you put the dry coffee grounds, and the water is in that chamber underneath. As the water boils when you put it on this heat source, some of the bubbles forming begin to push

water up that tube. So the hot water travels all the way up the tube out the other end, and it typically hits like a spreader plate or a drip plate of some sort that distributes this hot water, so it drips down onto the coffee grounds. UH. This hot water then seeps up the oils and caffeine as it does this and drips down through the perforations back into

the water chamber below, and the whole process continues. Uh Percolation, by the way, refers to filtering a liquid through some sort of porous material, and that actually means that most but not all coffee makers are actually percolators. But never mind that in America we just call the little bubbling stuff we see percolation. That's not really true, it's not accurate,

but it's what we call it. So the boiling water brewis the coffee, and eventually all that boiling water in the bottom of the pot is really brewed coffee as this process continues in the coffee recirculation also means that you typically end up with a pretty darn strong cup of coffee at the end, and that's because the coffee and the fresh water mixed together and the concentration of coffee increases the longer that the percolator is percle eating.

The stovetop or open flame versions also have a drawback. They typically are pretty bad about burning coffee as well, so it's a good efficient way to make a potentially

terrible cup of coffee. Much later. Other inventors came up with electric percolators, some of which designated a very small area of the bottom of the pot as a heat source, so that the area directly under where the tube is would become hot enough to cause bubbles to push water up the tube, just like in the stovetop version, but the rest of the water in the pot wouldn't be directly on a heat source, so cold water from the most of the pot would end up circulating in to

replace the hot water that's going up the tube, and you wouldn't be as likely to burn your coffee. However, like other percolators, this is another method where the fresh water and coffee mixed together and the coffee recirculates to the system, so you still get a pretty strong cup of coffee. Not necessarily a good one, but a very strong one. In the nineties seventies, Samuel Glazer and Vincent

Moroda got an idea. They thought of a way to create an automatic drip coffee maker, which was a kind of a way to create a pour over coffee without actually having to manually pour water over coffee grounds sitting in a filter over a craft. With the original Mr Coffee, you would put a filter in the coffee grounds basket.

You would fill that filter with coffee grounds, and then you would fill a chamber at the top of the machine with water, and you would put your coffee craft under the filter spout and you would turn on your coffee maker, and gravity did most of the work. Really. It would pull the water downward through this coffee maker.

The water would pass over heating elements that raised the temperature of the water dramatically before that water would then drip down over the coffee grounds in the filter, and then the water would go through the filter, carrying those oils nearromatics and caffeine into the graft. Later versions of the coffee maker changed up this design. They used a water reservoir that requires thermodynamics to move water up a tube to pass it over the coffee grounds, but it

no longer used a gravity fed system. So a typical coffee maker would have a little hole in the bottom of the water reservoir that you fill up with cold water. So cold water goes from the reservoir down this hole into an aluminum tube and it passes through a valve that allows water to travel only in that direction. It can't go backward, So in the aluminum tube, the cold

water passes near heating elements. These are coils of wire that heat up when you pass electricity through them because of electrical resistance, and that transfers heat to that cold water.

The heated water inside the aluminium tube begins to boil, so bubbles are forming, and because you have that valve that is blocking the bubbles from going back up to the reservoir, they can only travel forward up the tube, pushing water up as it goes up, and this hot water comes out of the top of the tube and then filters out to hit the coffee grounds, which then percolates right same same sort of thing as the percolator, except in this case you've got the supply of fresh

water separate from your finished coffee, because the hot water comes up, hits those coffee grounds, filters down through, carrying those oils and caffeine and everything, and then drips into the empty caraft underneath the filter, so you don't have to worry about the coffee mixing with fresh water and then recirculating through the system. And this was said to create a much more consistent cup of coffee, so you didn't end up with this burnt coffee taste or super

strong taste. Glazer and Moroda did call their device Mr Coffee. It represented a huge change in how Americans would make their breakfast beverage, and it was one of those inventions that made coffee far more convenient and cut back on the problems of burnt coffee in general. Though, the heating plate on most drip coffee makers can also burn coffee if you leave it turned on with the craft on

top of it. So after you finished brewing coffee with an automatic drip coffee maker, I recommend you turn off the coffee maker. I know that means that the heating plate is going to be off and that the coffee will gradually go cold. But one only brew as much coffee as you actually need, and to drink it not long after you brew it, because that's when it's best. Otherwise you're just you're just making things worse for yourself, honestly. Now,

there's a lot more we could talk about. Right There are the curig machines and their pods and the danger that that presents to the environment if you don't have compostable pods. There are French press machines which actually use infusion, not percolation for coffee. There are espresso machines which use pressurized hot water pushed through a coffee puck a puck

of coffee grounds. There are all these other things that we could talk about, but we're running along, so I'll do a look at some of the materials see if there's enough to justify a second episode, and if so, we'll follow this up with another coffee themed episode of tech Stuff, and if not, maybe I'll pair it with something else. Maybe we'll do sort of you know, breakfast tech, and we'll include some of the coffee stuff I didn't

talk about and some other technologies. In the meantime, If you guys have suggestions for things I should tackle on tech Stuff, whether it's a specific technology, a trend in tech, maybe it's a company that you want me to talk about, whatever it might be, let me know on Twitter. The handle to use is tech stuff H s W and I'll talk to you again really soon. Text Stuff is an I Heart Radio production. For more podcasts from I Heart Radio, visit the I Heart Radio app, Apple Podcasts,

or wherever you listen to your favorite shows. Three