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How Do You Decaffeinate Coffee Beans?

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Many of us can't start our days without at least one cup of coffee, but we don't really give the magic beans much thought after we drain our mugs. Let's take a look at a few questions you might have about the intricacies of the coffee business.

How do you decaffeinate coffee beans?

There are a number of ways to cut the eye-opening power of a cup of joe, but the methods are basically pretty similar. First, processors use water or steam to swell the green beans, then they extract the caffeine using a solvent. Water, ethyl acetate, methylene chloride, or highly pressurized carbon dioxide strip the caffeine away from the beans, which are then steamed to remove any solvent residues and dried.

Do these methods get all the caffeine out?

Not quite, but it strips away quite a bit. According to U.S. law, any decaffeinated coffee must retain less than 2.5% of its caffeine, while in the EU only 0.1% of decaf beans' dry weight can be caffeine. According to the International Coffee Organization, a cup of decaf has around 3 mg of caffeine in it, while the average 5 oz. cup of drip coffee contains 115 mg.

What happens to all the caffeine that gets stripped from the coffee?

It would be a shame for all that caffeine to go to waste—there are undercaffeinated children in third-world countries, you know—so processors save and sell the jittery gold. Pharmaceutical companies and soft drink makers are the big customers for the extracts; although the kola nut provides a bit of a jolt for your cola, the majority of the caffeine in your soda comes from the addition of caffeine extracted from coffee beans during decaffeination.

Can you age coffee?

You don't want to age that bag of beans you picked up at your local coffeehouse, but coffee producers have aging down to a science. Green coffee beans can take up to 10 years of aging in special warehouses; over time their acidity dies down as their body increases.

A special type of aging in tropical regions results in what's known as "monsooned" coffee. Processors leave beans in open-sided warehouses where they will be exposed to the moist air and winds of monsoon season, which can cut down on acidity and add body in just a few weeks. The most common example of this practice is monsooned Malabar, a prized coffee from southern India.

Has coffee ever been illegal?

The Ottoman Empire cracked down on coffee and coffeehouses at various times, but the most notable ban came under Murad IV, who was the Sultan of the Ottoman Empire between 1623 and 1640 and probably wasn't described as "a fun guy" by any of his subjects. Murad banned tobacco use in the empire and would even walk around in plain clothes looking for smokers. If the emperor caught someone lighting a butt, his majesty would beat the person with his mace.

Tobacco wasn't Murad's only nemesis, though. When he realized that his subjects were congregating in coffeehouses to grouse about having an absolute whack job for an emperor, he banned coffee in the entire Ottoman Empire. Getting caught with a cup of joe earned subjects a beating. Hitting the java a second time got you sewn in a sack and dumped into the waters of the Bosphorus.

Where did the cappuccino get its name?

The delightful concoction of espresso, hot milk, and foam takes its name from the Capuchins, a Roman Catholic order of friars. According to the Oxford English Dictionary, the drink's color resembled the brown robes worn by the Capuchins, so Italian coffee fans began to call the drink the cappuccino.

Where did we get the name "mocha"?

From a port in Yemen. During the 19th century, Mocha was an important port in Yemen where sailors could load their holds with Mocha Java, a tasty blend of local Arabian coffee and beans from the Indonesian island of Java. The renowned blend wasn't cheap, though, so other coffee roasters attempted to replicate the subtle chocolate notes of Mocha Java by adding chocolate directly to lesser beans. Over time, this combination of chocolate and coffee took on the name "café mocha" as a tribute to the port that inspired it.

Why do some coffees market themselves as "arabica"?

Although the name sounds exotic, "arabica" doesn't refer to a special roasting process or preparation. Instead, Coffee arabica is the scientific name of the species of coffee that produces over 60 percent of the world's beans. Arabica coffee is generally regarded as being tastier and less bitter than the other main commercial species, Coffee canephora, but it is more susceptible to disease. While Coffee canephora doesn't have the same yummy taste, it is a hardier plant and produces beans with more caffeine and a full-bodied mouthfeel.

Is there an actual Maxwell House?

There used to be. When it opened in 1869, the Maxwell House Hotel was Nashville's largest and swankiest hotel, and through the early 20th century it pulled in famous guests like Teddy Roosevelt and various members of the Vanderbilt clan. The coffee took its name from the hotel, and for years ad men claimed that the "Good to the Last Drop" slogan originally came from Teddy Roosevelt after he slurped down a cup of the brew. Modern research, though, has suggested that the slogan came from a particularly inspired ad exec. A fire destroyed the Maxwell House in December 1961.

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iStock // Ekaterina Minaeva
Man Buys Two Metric Tons of LEGO Bricks; Sorts Them Via Machine Learning
May 21, 2017
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iStock // Ekaterina Minaeva

Jacques Mattheij made a small, but awesome, mistake. He went on eBay one evening and bid on a bunch of bulk LEGO brick auctions, then went to sleep. Upon waking, he discovered that he was the high bidder on many, and was now the proud owner of two tons of LEGO bricks. (This is about 4400 pounds.) He wrote, "[L]esson 1: if you win almost all bids you are bidding too high."

Mattheij had noticed that bulk, unsorted bricks sell for something like €10/kilogram, whereas sets are roughly €40/kg and rare parts go for up to €100/kg. Much of the value of the bricks is in their sorting. If he could reduce the entropy of these bins of unsorted bricks, he could make a tidy profit. While many people do this work by hand, the problem is enormous—just the kind of challenge for a computer. Mattheij writes:

There are 38000+ shapes and there are 100+ possible shades of color (you can roughly tell how old someone is by asking them what lego colors they remember from their youth).

In the following months, Mattheij built a proof-of-concept sorting system using, of course, LEGO. He broke the problem down into a series of sub-problems (including "feeding LEGO reliably from a hopper is surprisingly hard," one of those facts of nature that will stymie even the best system design). After tinkering with the prototype at length, he expanded the system to a surprisingly complex system of conveyer belts (powered by a home treadmill), various pieces of cabinetry, and "copious quantities of crazy glue."

Here's a video showing the current system running at low speed:

The key part of the system was running the bricks past a camera paired with a computer running a neural net-based image classifier. That allows the computer (when sufficiently trained on brick images) to recognize bricks and thus categorize them by color, shape, or other parameters. Remember that as bricks pass by, they can be in any orientation, can be dirty, can even be stuck to other pieces. So having a flexible software system is key to recognizing—in a fraction of a second—what a given brick is, in order to sort it out. When a match is found, a jet of compressed air pops the piece off the conveyer belt and into a waiting bin.

After much experimentation, Mattheij rewrote the software (several times in fact) to accomplish a variety of basic tasks. At its core, the system takes images from a webcam and feeds them to a neural network to do the classification. Of course, the neural net needs to be "trained" by showing it lots of images, and telling it what those images represent. Mattheij's breakthrough was allowing the machine to effectively train itself, with guidance: Running pieces through allows the system to take its own photos, make a guess, and build on that guess. As long as Mattheij corrects the incorrect guesses, he ends up with a decent (and self-reinforcing) corpus of training data. As the machine continues running, it can rack up more training, allowing it to recognize a broad variety of pieces on the fly.

Here's another video, focusing on how the pieces move on conveyer belts (running at slow speed so puny humans can follow). You can also see the air jets in action:

In an email interview, Mattheij told Mental Floss that the system currently sorts LEGO bricks into more than 50 categories. It can also be run in a color-sorting mode to bin the parts across 12 color groups. (Thus at present you'd likely do a two-pass sort on the bricks: once for shape, then a separate pass for color.) He continues to refine the system, with a focus on making its recognition abilities faster. At some point down the line, he plans to make the software portion open source. You're on your own as far as building conveyer belts, bins, and so forth.

Check out Mattheij's writeup in two parts for more information. It starts with an overview of the story, followed up with a deep dive on the software. He's also tweeting about the project (among other things). And if you look around a bit, you'll find bulk LEGO brick auctions online—it's definitely a thing!

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Scientists Think They Know How Whales Got So Big
May 24, 2017
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It can be difficult to understand how enormous the blue whale—the largest animal to ever exist—really is. The mammal can measure up to 105 feet long, have a tongue that can weigh as much as an elephant, and have a massive, golf cart–sized heart powering a 200-ton frame. But while the blue whale might currently be the Andre the Giant of the sea, it wasn’t always so imposing.

For the majority of the 30 million years that baleen whales (the blue whale is one) have occupied the Earth, the mammals usually topped off at roughly 30 feet in length. It wasn’t until about 3 million years ago that the clade of whales experienced an evolutionary growth spurt, tripling in size. And scientists haven’t had any concrete idea why, Wired reports.

A study published in the journal Proceedings of the Royal Society B might help change that. Researchers examined fossil records and studied phylogenetic models (evolutionary relationships) among baleen whales, and found some evidence that climate change may have been the catalyst for turning the large animals into behemoths.

As the ice ages wore on and oceans were receiving nutrient-rich runoff, the whales encountered an increasing number of krill—the small, shrimp-like creatures that provided a food source—resulting from upwelling waters. The more they ate, the more they grew, and their bodies adapted over time. Their mouths grew larger and their fat stores increased, helping them to fuel longer migrations to additional food-enriched areas. Today blue whales eat up to four tons of krill every day.

If climate change set the ancestors of the blue whale on the path to its enormous size today, the study invites the question of what it might do to them in the future. Changes in ocean currents or temperature could alter the amount of available nutrients to whales, cutting off their food supply. With demand for whale oil in the 1900s having already dented their numbers, scientists are hoping that further shifts in their oceanic ecosystem won’t relegate them to history.

[h/t Wired]