How Coffee, Coffee Machines, Espresso Machines & More Are Made! | How It’s Made | Science Channel

Espresso was invented in Italy in the 1880s because people wanted a quick cup of coffee. Special machines were developed to make espresso. It could be produced in seconds, there was no waiting around for coffee to percolate. Soon the appeal was more than expediency. Making good espresso coffee is a science and today we have the technology. Professional machines balance temperature and steam pressure to produce espresso with kick and crema. To make a professional espresso machine, computer-programmed tools carve high-carbon steel sheets into different shapes, creating parts that will be the framework for the espresso machine. The tooling also cuts holes for screws, bolts and components like the steam tap. An employee then serves up a freshly cut control panel to a hydraulic press machine. It bends the panel to the correct profile and creates tabs for assembly. This is before and after bending. After bending the other panels, they assemble the framework. The worker attaches a receptacle to capture and contain water runoff. He installs meters that will control the flow of water, releasing the correct amounts for long or short espressos. He turns the base right side up and screws the side framework to it. He attaches the front panel to the sides. The espresso machine's framework is now in place. Next up are the group heads, the parts that will shower pressurized hot water through the ground coffee. The worker installs valves that will regulate the flow of the water. They'll also release built-up pressure so that the filter holders can be removed after brewing. The group heads fit into slots in the front of the framework. He secures them to it with nuts at the back. He now places a substantial copper and brass boiler in the espresso machine chassis and connects the water lines. The tank will generate steam to froth milk for cappuccinos and also supply hot water for tea. Heat exchangers run through the boiler to supply the hot water for brewing. He connects copper pipes to the heat exchanger outlets on the boiler and links them to the group heads. The pipes have been pre-bent in order to route them into the group heads. He tightens the fitting for the hot water tap. The pump that pressurizes water is next. He screws it to one side of the framework. A worker then wires the electronics to the front of the machine. The employee fits the control panel to the front framework. He slips rubber molding around the steam levers to trim them up and screws knobs onto the levers. He tucks a heating element into the upper part of the machine. This element is for warming cups stacked on the top because espresso will stay hotter if served in warm cups. A worker then encases the steel espresso machine in polycarbonate molded panels. These plastic parts have a slightly rounded profile and make the espresso machine look less boxy. He seats a steel drip tray under the group heads and he places the cup tray over the heating element. The machine is ready for the filter basket holders. They're equipped with winglets which hook into the group heads. This professional espresso machine can now be put to the test. He confirms that there are no leaks in the hydraulic circuitry and that the machine is in good working order. After all that work it's time for a coffee break. Coin operated coffee machines are a staple in offices and public places. Years ago these machines just weren't able to produce consistent brews and there also wasn't much choice in brewing style. But today even finicky java junkies drink machine coffee because the latest machines have mastered the art of making delicious coffee one cup at a time. This office coffee machine actually makes several different types of hot beverages and if your employer pre-pays you don't have to insert any coins. Production begins with a sheet of steel about six and a half feet long by about one and a half feet wide. This flat as it's called will become the top and side sections of the machine's casing. A computer guided punch press makes dozens of perforations for ventilation and for the various fittings the machine will need in order to function. A worker puts another sheet of steel into a press. This press bends the metal into 90 degree angles. This piece will become the bottom of the casing. A worker uses a spot welding machine to assemble what's called the base panel. This will later house a waste chute, overflow sensors, and wires. Another worker coats the casing with an epoxy based paint powder. This process statically charges the powder and draws it to the metal like a magnet. Excess powder falls into a barrel below. Here a worker installs a fan that'll vent the steam and heat generated inside the machine. Another worker assembles one of the two coffee delivery mechanisms called augers. When the machine's on they move the ground coffee to the He installs the augers into what's called the dual hopper. The hopper's two sections will hold up to six pounds of different coffee blends such as dark and light roasts. Next he installs what's called an agitation wheel. This plastic wheel helps move the ground coffee along and prevents it from getting stuck. The worker then aligns plastic couplings on the augers to mate with the ingredient dispenser. The dual hopper attaches to the ingredient dispenser with one screw in a pivoting bracket. Workers also connect power wires to the dispenser's motor and to a water inlet valve. Next they install a heater and temperature sensor inside a plastic water tank that's nearly two gallons large. This 1100 watt heater keeps the water at 200 degrees Fahrenheit just below boiling. That's the optimal temperature for extracting flavor from ground coffee beans. After applying stickers warning service technicians to turn off the machine before draining it, a worker installs three outlet valves. One to dispense hot water for tea, one for coffee, and another for hot chocolate. Next come stainless steel rods to monitor the water level inside the tank. They trigger an automatic refill mechanism. The worker connects power wires to the brewer motor. Then she mounts what's called the whipper mixing bowl. This aligns with the chocolate syrup dispenser to prepare the hot chocolate. Next she installs the brewer motor assembly into the machine's casing. This is the coffee machine's 15-button selection panel. It lets you select what type of hot drink to brew, in what cup size, and when to start. The panel also displays the prices when the coffee's not on the house. Once that's hooked up, workers test the chocolate syrup delivery system. They run water through it to ensure it doesn't leak. They also test to see if the system dispenses the correct dose of syrup. One dose is a half ounce, a tablespoon. A small cup of hot chocolate requires two doses. A large cup requires four. Now they install the brewer. It works much like a French press coffee maker, brewing a separate batch for each cup. To test it, they run water through it and make sure the selection panel works properly. By testing the panel with the coffee machine closed, they ensure the circuits are properly aligned behind the selection buttons. Depending on how strong you select your coffee, a dispenser releases between 0.2 and 0.6 ounces of ground coffee into a reusable nylon filter. A piston then forces hot water through the filter for 10 to 20 seconds, depending on the size of the cup. This process extracts the flavor of the ground beans. The machine then scrapes away the coffee grinds and throws them down the built-in waste chute. Then it prepares for the next customer and the next delicious cup. According to legend, a goat herder in Ethiopia discovered coffee around 850 A.D. Eventually, the beverage reached Italy, where the first European coffee house opened in 1645. Today, about 2 billion cups of coffee are drunk each day around the world, making coffee the second most valuable trading commodity after oil. Coffee's flavor depends on the region where it grows and the way coffee makers roast and blend the beans. Here in Costa Rica, they grow coffee plants from sprouted seeds kept in containers for a full year before they transplant them into the field. From seed to first harvest takes about two years. Coffee plants flower over the course of three days, covering the fields with fragrant jasmine-like blooms. Over six months time, the buds grow and ripen into red cherries that contain the coffee bean. Pickers harvest the red cherries, leaving the green ones to ripen. They'll return to pick the cherries from the same plant five times in three months as they ripen. Pickers do their best to have no more than two green for every hundred red cherries they harvest. They empty their bins into bags and load them into trucks. Each bin produces about four and a half pounds of coffee beans, enough to make about 200 cups of coffee. The fresher the berry, the better the flavor. Cherries picked in the morning are at the wet mill, ready for processing that afternoon. At the wet mill, water channels wash the cherries and drop them off at a worm screw. It loads them into a pulping machine to remove the outer skin and fruit. A rotating drum presses the cherries against the wall of the pulper and squeezes out the bean. From the pulping machine, the beans flow in water to two large rotating cylinders. They sift the beans to separate them from any of the hard green cherries that pass through the pulping machine. Next, the beans bathe in more water, which draws out a thick sugary substance known as miel, honey in Spanish. The coffee maker then feeds the washed beans to make sure they're no longer sticky. The beans then drop into the drying bin below. Workers now lay out the beans to dry in the traditional way, outdoors on a cement patio. For four days, they rake over the beans as they dry in the hot sun. At night, they let the beans rest to extract the most flavor. Once the beans are dry, they go into a milling machine. Inside, large stones grind away the parchment-like hull from the bean. Drying methods vary among coffee makers. They're a closely guarded secret. The beans can also dry mechanically in rotating drums that pump in heated air. Workers closely monitor the process and empty the drums when the beans are dry. A supervisor smells them to check for a vinegar-like odor. That would mean the beans are fermenting, a result of improper drying. The dry beans have their husks removed, then go onto an oscillating table that separates them by weight into three grades, the heaviest being the first grade beans. Workers pour out each grade into burlap bags. Their contents must weigh in at 152 pounds per bag. Finally, they stitch them up and stack them for shipping. Next, we'll see the whole process that turns these green coffee beans into a steaming cup of gourmet coffee. This German company's coffee filters are made of 100% cellulose fiber, harvested from slow-growing pine and spruce trees in the forests of southern Scandinavia. Because it produces paper, that lets 100 milliliters of water pass through it in approximately 40 seconds, an optimal saturation rate for producing good coffee. 30% of the paper's cellulose content comes from leftovers from earlier production. The other 70% is raw cellulose fiber. The materials go into a machine called a pulper, which works like a giant food processor. It purees the raw material and blends it with hot water to make a fiber soup called pulp. An 80-meter-long paper-making machine will process the pulp into paper. The machine spreads a three-centimeter-thick layer of pulp across a three-meter-wide belt made of wire mesh. Water jets cut a straight edge on both sides. As moisture drains down through the belt, the pulp forms a soggy sheet of paper that has a water content of 80%. All this happens at an astounding pace, the machine laying down some 400 linear meters of pulp per minute. The paper then enters the machine's next station, where heavy compression rollers squeeze out almost half the water. At the next station, a tool applies a crepe texture. This increases the surface area of the paper, which improves the speed of filtration. The paper now enters the machine's drying station, where 38 steam-heated rollers, their surface temperature approximately 120 degrees Celsius, remove the excess moisture. As the finished paper exits the machine, a camera registers the location of holes, dirt, or other defects that have to be cut out. It takes the machine 45 minutes to produce an 18-kilometer-long roll of filter paper. The next step is to transfer the roll to a cutting machine, which slices it into five narrower rolls, each 60 centimeters wide, to fit in the filter-making machine. As the narrower roll enters that machine, a sensor verifies that the sheet is aligned correctly. At the first station, needles, each one a mere hundredth of a millimeter in diameter, pierce tiny holes in the paper to enhance the quality of filtration. At the next station, a stamp embosses the company logo in the paper. A knife slices the paper in half, creating two side-by-side production lines from this point onward. Each line immediately enters a folding station, where guides gradually fold the flat sheet in half. A roller embosses a seam connecting the two layers of paper along the bottom and side. Then a second roller cuts the conical shape of the filter out of the paper. The machine produces 4,000 filters per minute. The next station cuts the filters apart and collects the leftover paper to be recycled into pulp. The filters made from this roll of paper continue on to an automatic counting machine, which divides them into stacks of 80. The machine feeds the stacks to the packaging line. The automated packaging machine aligns each stack with a flattened box it opens with a vacuum. Then it compresses and inserts the filters under the watchful eye of a sensor. If the sensor detects the filters are in the wrong position, or not in the box at all, it triggers the machine to eject that box from the line. The factory produces a few types of filters designed to brew coffee in different ways. How it sets the pulper to process the cellulose ultimately determines how the filter performs. For example, to make filters designed to brew strong coffee, the factory processes the cellulose more finely. This produces paper that drains more slowly, keeping the water in contact with ground coffee longer for stronger flavor. The earliest tools for roasting coffee beans were pans you'd hold over hot coals or an open fire. Today, coffee roasting is a far more sophisticated process, using large, often fully automated machines with built-in gas burners that heat air to roast the beans. This coffee roaster is both programmable and manually adjustable by touch panel. The roast master can tailor the temperature and roasting time to influence flavor, acidity, and other characteristics. To shape the roast chamber, workers feed a sheet of stainless steel through a sheet metal roll. The roast chamber is the drum in which the beans roast by convection heat. A paddle inside moves the beans around so that they roast evenly. The next step is to weld the rolled sheet into a cylinder. Then they grind and polish the welds until they're flat, smooth, and shiny. They make the cooling tray in a similar way, but with a support band welded to the top. The cooling tray is the drum into which the hot beans drop when they exit the roast chamber. Stirring arms circulate the beans as a fan draws air through the tray to cool them. Certain parts are cut from a stainless steel sheet. Stainless steel is the ideal material, not only because it's stylish, but also because it's durable and corrosion resistant. This computer-guided laser cutter is slicing out a safety component called the heat shield, which prevents the roast master from accidentally touching a hot surface. The heat shield, like many other parts cut from stainless steel sheets, has to be formed to a very precise shape. Workers bend angles and curves into the metal with a press break. Another component, the trier, lets you draw a sample of beans during roasting. A craftsman constructs the trier by welding various smaller parts to a piece of stainless steel tube, then meticulously grinding and polishing the welds until they're smooth. This high-pressure water jet cutter also cuts parts from stainless steel sheets. This component is one of six flights, part of the paddle that lifts and mixes the beans inside the roast chamber so that they roast evenly. To form the flights to the required shape, a worker curves them one at a time in a press. The welder places all the paddle components into a specialized fixture, which positions them correctly. First, he aligns the spokes to the paddle shaft, then he welds them in place. He positions the flights, clamps them securely, and welds them on. The combination of inner and outer flights lifts the beans into the A custom-designed grinding machine hones the flights to produce a clearance of mere millimeters between the edge of the paddle and the wall of the roast chamber. This ensures the paddle is wide enough to pick up every last coffee bean without touching the wall while rotating. Once they install the paddle, they close up the roast chamber with a faceplate. Alignment pins ensure the faceplate is properly positioned. The paddle shaft protrudes through a bearing in the faceplate. The assembly team uses a hoist to lift the heavy chamber and position it on top of the coffee roaster's stainless steel support frame. They install the heat shield that was cut by the On top, they mount the machine's funnel-shaped hopper. It feeds the unroasted coffee beans to the roast chamber below. Thankfully, you don't have to climb up to the hopper, lugging a heavy bag of beans. The hopper's lid has a tube which connects to a vacuum system that draws the coffee beans up through a plastic hose. On the front of the roasting chamber, they hang a hinged discharge door that has a viewing window. They plug in a sensor that measures the temperature of the beans in the roasting chamber and sends that information to the machine's computer. More to come after this coffee break. These coffee pods are designed to be composted after use. They offer the convenience of a quick coffee without long-term landfill consequences. The process of making coffee pods starts with bags of unroasted beans from different parts of the world. These beans will be combined to create specific blends, but first they must be thoroughly tested and graded. A technician inhales the aroma to sniff out defects. He examines the physical condition of the beans. He's looking for insect damage or fragmentation. If he finds too many defects, the lot will be rejected. Too much moisture would be another indication that the coffee beans are substandard, so he measures the water content using an electronic analyzer. He roasts samples of the beans in these mini roasters. This unlocks the flavors and aromas in the green coffee beans. The color deepens. The beans harden and double in size due to the release of gases and water vaporization. For lighter, milder beans, he does a shorter roast. For darker, more intensely flavored beans, he roasts them a little longer. He inspects the color frequently and, when satisfied, he empties the beans into receiving trays. Fans underneath cool the beans and stop the cooking. Roasting has transformed the bitter green beans into something entirely more flavorful. The technician grinds small amounts into different glasses in order to prepare for a flavor analysis known as cupping. The Q grader takes over. He's a certified coffee taster. He inhales the bouquet of the coffee and assesses it. He then pours hot water onto the coffee and lets it steep. The grounds float to the surface and form a thick crust. He breaks the crust with a spoon and inhales again. Then, after skimming off the grounds, he slurps the coffee and ponders its flavor, body, and acidity. He grades the samples accordingly. The highest grade beans will now be made into coffee pods. Big batches tumble in a computer-controlled roaster. The computer slowly increases and then drops the temperature for the desired result. The roaster ejects the beans onto a perforated pan and rotating paddles mix them to dissipate the heat. In this industrial grinder, rollers pulverize the coffee beans to a specific granulation. Too fine and the coffee will taste bitter, too coarse, and the full flavor won't be extracted. To test the granulation and density, a technician dispenses some of the coffee into a one-pint container and then weighs it. If the coffee is too heavy and compressed, water won't flow easily through the coffee pod. Once it passes the density test, the coffee is packed into pods. The filter material unwinds through tensioning rollers towards the assembly machine. The pod rings, made from plant-based plastic, head in the same direction. A pusher moves the rings into slots on a revolving drum. The system pulls the mesh filter material over the pod rings. Heated devices descend as the drum turns and seal the mesh to the rings. Formers stretch the mesh to shape it into filter cups. As the drum continues to turn, depositors fill rows of the mesh filter cups with coffee. Paper lid material unwinds from the other side and heat sealers fuse it to the pods. At the same time, the sealing heads punch out the pods, separating them from the mesh and the excess lid paper. The coffee is now encased in pods. Exiting the drum, an overhead system moves the pods forward to be weighed. This mechanized system produces 220 coffee pods a minute. Each will provide a quick caffeinated pick-me-up. After water, tea is the most consumed beverage in the world. The different types are determined by the degree to which the producer lets the harvested leaves oxidize before drying them. Green tea, for example, is barely fermented, whereas black tea is greatly fermented. Oolong falls somewhere in between. In Chinese, oolong means black dragon. It's a semi-oxidized tea, fermented more than green tea, yet less than black tea. Its taste, aroma, and color from light yellow to dark red vary according to how the tea leaves are processed. This amber oolong produced in Like most teas, oolong is made from the leaves of a flowering plant species called Camellia sinensis. Harvest time is during the plant's peak growing season, which in Thailand is from May to November. Workers handpick what's known as the flush, a grouping of two young leaves and a bud which grows out the top of the plant. At this time of year, the plant produces a new flush every 7 to 15 days. An experienced tea master directs every phase of the processing, the first step of which is called solar withering. Workers bring the leaves into a glass-roofed building, then spread them out in the sun for 15 to 20 minutes. This kick-starts the oxidation fermentation process as the chlorophyll enzymes inside the wilting leaves start breaking down. At the same time, the moisture inside begins evaporating. Workers keep moving the leaves around to ensure a thorough exposure to the sun. Then they gather up the leaves for step two, indoor withering. The leaves lie on bamboo trays for 6 to 8 hours, where gently stirred every 2 hours, they oxidize further. Step three, disruption. The leaves go into a rotating drum. As they tumble, they bruise and tear. This breaks down the cell structures, enabling oxygen to penetrate deep inside, greatly accelerating fermentation. This also releases the leaf juices, which help draw out the taste of the tea. When the tea master determines the leaves have sufficiently oxidized, they stop the oxidation process by tumbling the leaves in a gas-heated dryer for 10 to 15 minutes. This fourth step of the process is called fixation, because it fixes the oxidation at the desired level, which can be anywhere from 8 to 85 percent, depending on the variety of oolong in production. This is the most critical part of the process, because it determines the tea's taste, aroma, and color. The next step forms the tea leaves into tiny pellets. First, workers shake the leaves on a sieve to filter out the dust-like particles. Then they bag the leaves in a cotton cloth and place them, first in a kneading machine, then afterward in a rolling press. Kneading and rolling the bag twist the leaves inside into tiny pellets. Forming these pellet shapes intensifies the flavor of the tea, and when the tea is steeped in hot water, releases that flavor slowly. They repeat the sieving, kneading, and rolling cycle up to 35 times until the tea master is satisfied with the result. Then, and only then, does the final step begin, firing. They transfer the tea to an oven in which it undergoes three drying cycles of 20 minutes each, at a temperature of approximately 210 degrees Fahrenheit. This dries the damp tea, reducing the moisture content to the target level of less than 5%. The firing also brings out the fragrance. The traditional way to brew oolong is in a clay teapot, using about two teaspoons of tea per cup. Ideally, the water should be 190 to 210 degrees Fahrenheit. Steeping time is from 3 to 10 minutes, and you can brew the same leaves up to five times. People generally like their coffee either hot or iced, hence the need for the thermal coffee pot. Pour in hot coffee, and the pot holds in heat, keeping the coffee at that temperature for a good half hour. The trick to a thermal coffee pot is in the construction. Both the body and lid have a double wall, two layers of stainless steel. Between them is a gap, just 5 to 6 millimeters. The air in this gap insulates the inner wall, trapping the heat inside the pot. They start with a stainless steel sheet, just 1.2 millimeters thick. The first step is to cut it into smaller pieces on a mechanical press. To make the coffee pot's body, they cut it into strips, then each strip into squares measuring 8 by 8 inches. Then they put each square in another mechanical press. It stamps the square onto a circular die, which cuts it into a disc. They'll now use this disc to make the outer wall. They run the disc through a lubricator that coats the surface with oil to aid the next step. On a machine called a hydraulic deep drawing press, the machine's molders draw the flat disc into a three-dimensional shape. This stretches the stainless steel fibers to a very fragile state. They strengthen the piece by what's called thermic normalization, heating the metal to 1,800 degrees Fahrenheit, then letting it cool to room temperature. This process restores the original molecular structure of the stainless steel, so it can be shaped further without breaking. But first, they even out the jagged rim with the trimmer. Then they return the wall to the deep drawing press, outfitted with a differently shaped molder. The second drawing tapers the wall to a more rounded shape and forms a base to make the bottom perfectly flat. Then it's back to the trimmer, outfitted with a different tool this time to smooth the rim. They repeat the same steps to make the coffee pot's inner wall. The deep drawing press pulls the stainless steel disc into a slightly different shape, with the lip protruding to one side. They heat the wall in the induction oven to restore the molecular structure before shaping the metal further. Then they place the wall in a mold and release a press. This shapes the protruding lip into a spout. Then they transfer the wall to another press, which stamps it with a die, cutting off excess metal. They check to make sure that the inner and outer walls fit together properly. If everything's fine, they polish both walls inside and out. A little polishing paste applied with a sisal brush on the polishing wheel has the surfaces glistening in no time. The surface is now perfectly smooth and ready for welding. The first part they weld is the coffee pot's stainless steel handle. They shape it with two strikes of a press, then polish. They use a spot welder to fuse the handle to the pot's outer wall. Then they turn the wall upside down to stamp the manufacturer's logo into the bottom. Now the assembly. They place the inner wall on a fixture, then the outer wall over it. A press pushes the inner to the correct depth. Then they weld along the rim of the outer wall, fusing it to the inner one. The coffee pot's lid also has double walls for insulation. They weld a hinged lever to the lid and the adjoining part of the hinge to the coffee pot body. Then they gently hammer a pin through the hinge, riveting the ends of the pin so that it can't fall out. After a thorough cleaning in a dishwasher, the coffee pot is ready to use.