How Do They Dye the Chicago River Green for St. Patrick's Day?

iStock.com/stevegeer
iStock.com/stevegeer

It wouldn’t be a St. Patrick’s Day celebration in the Windy City without 400,000 spectators crowding the banks of the Chicago River to “ooh” and “aah” at its (temporarily) emerald green tinge. But how do officials turn the water green?

First, a bit of history: The dyeing tradition became an annual thing nearly 60 years ago, in 1962, but its real origins go back even further. In the early days of his administration as Mayor of Chicago, Richard J. Daley was a man on a mission to develop the city’s riverfront area. There was just one problem: The river itself was a sewage-filled eyesore. In order to get to the bottom of the city’s pollution problem and pinpoint the exact places where waste was being discarded into the waterway (and by whom), Daley authorized the pouring of a special green dye into the river that would allow them to see exactly where dumping was occurring.

Fast-forward to late 1961 when Stephen Bailey—part of the Chicago Journeymen Plumbers Local, the city’s St. Patrick’s Day Parade chairman, and a childhood friend of Daley’s—witnessed a colleague’s green-soaked coveralls following a day of pouring Daley’s dye into the Chicago River. That gave Bailey an idea: If they could streak the Chicago River green, why not turn it all green?

Three months later, revelers got their first look at an Ecto Cooler-colored river when the city poured 100 pounds of the chemical into the water. They got a really good look, too, as the river remained green for an entire week.

Over the next several years, the same practice was repeated, and again it was carried out by the Plumbers Local. The only difference was that the amount of dye used was cut in half over the next two years until they finally arrived at the magic number: 25 pounds of dye = one day of green water.

Unfortunately, the dye that was intended to help spot pollution was an oil-based fluorescein that many environmentalists warned was actually damaging the river even more. After fierce lobbying, eco-minded heads prevailed, and in 1966 the parade organizers began using a powdered, vegetable-based dye.

While the exact formula for the orange powder (yes, it's orange until it's mixed with water) is kept top-secret—in 2003 one of the parade organizers told a reporter that revealing the formula would be akin to “telling where the leprechaun hides its gold”—there are plenty of details that the committee lets even non-leprechauns in on.

The dyeing process will begin at 9 a.m. on the morning of the parade—which this year is Saturday, March 16 (it's always held on a Saturday) when six members of the local Plumbers Union hop aboard two boats, four of them on the larger vessel, the remaining two on a smaller boat.

The larger boat heads out onto the water first, with three members of the crew using flour sifters to spread the dye into the river. The smaller boat follows closely behind in order to help disperse the substance. (The best place to catch a glimpse is from the east side of Michigan Avenue, or on Upper and Lower Wacker Drive between Michigan Avenue and Columbus Drive.)

Approximately 45 minutes later, voila, the Chicago River is green—but don’t expect it to stay that way. These days, the color only sticks around for about five hours. Which is roughly the same amount of time it takes to get a perfectly poured pint of Guinness if you venture out to an Irish pub on St. Patrick’s Day.

A version of this article first ran in 2017.

Have you got a Big Question you'd like us to answer? If so, send it to bigquestions@mentalfloss.com.

What Exactly is Christmas Tree Flocking?

iStock.com/Spiderstock
iStock.com/Spiderstock

Of the many curious holiday traditions (figgy pudding? wassailing?), one of the oddest has to be spraying down small trees with a mixture of adhesive and cellulose fibers to satisfy our longing for a white Christmas.

That’s what’s happening when you adorn a tree with artificial snow, otherwise known as flocking. And yet, when decorated and lit up, there’s something beautiful and warmly nostalgic about a well-flocked Christmas tree. Here’s how professionals manufacture this Christmas miracle.  

The History of Flocking

We’ve been trying to get that snowy look on Christmas trees for longer than you might think, dating back to the 1800s using substances like flour or cotton. A 1929 issue of Popular Mechanics recommended varnish, corn starch, and flakes of the silicate mineral mica. 

But tree flocking as we know it really caught on in the late 1950s and 1960s, along with aluminum trees and other glitzy (if not natural-looking) decor of the post-war boom. General Mills marketed Sno-Flok home kits, to be applied using a gun that attached to a vacuum cleaner.

Such home kits are not so popular these days, says Tom Leonard, owner of Peak Seasons, one of the country's largest manufacturers of Christmas tree lots supplies and tree flock. Flocking itself, however, has retained a level of appeal. “Sunbelt states use a lot of it because there’s no snow there,” Leonard tells Mental Floss. “It’s tremendously popular. The West Coast, the South, and the Southeast, the vast majority of it is sold in those zones.”

The Science of Flocking

So what exactly is flocking? At its core, flocking means attaching tiny fibers to a surface to create texture (the process is also used in fashion, home decor, and crafts). The Peak Seasons recipe includes paper pulp as fiber, corn starch as adhesive, and boron as a flame retardant—there’s a safety benefit to flocking.

And the company makes a lot of it. Leonard says they're the largest manufacturer of flock in the United States and Europe. “I don’t want to share [how much], but we sell lots of flock. I mean truckloads and truckloads.”

Based in sunny Riverside, California, Peak Seasons starts with paper and a grinder. “It’s like a big roll of toilet paper and it weighs a ton and you feed it into a machine and it comes out a powder,” Leonard says. The exception is certain bright colors—flock comes in white, black, pink, ice blue, royal blue, red, green, gold, and purple—which require cotton fibers instead of paper to hold the dye. The final product is almost like baby powder, shipped all over the country in large, cement-bag-sized bags.

From there you need to affix the stuff in a nice even coat, which is where flock machines like the Mighty Sno-Blower come in. They’re basically big tanks that hold varying amounts of flock depending on the model, plus a mechanism at the bottom to fluff up the powder. The machine then pumps the powder through a hose, and a gun at the end mixes it with a mist of water.

And that’s how flock is born.

The Art of Flocking

You don’t have to go with a professional flocker, or even use manufactured flock. There are all sorts of DIY recipes that include things like soap flakes or even desiccated coconut flakes. But if you do go pro, you want to be in the hands of someone like Paul Iantosca, who has been flocking trees in the Boston area for 20 years.

Flocking one tree in bright purple (white is still most popular), Iantosca first sprays it down with water. Then, in an area closed off with plastic sheeting, he fires up the blower and blasts the tree evenly with what looks like a purple fog. The stuff gets everywhere. He wears a mask to keep it out of his nose, but some high-volume flockers wear full protective coveralls. 

The tricky part to flocking is that you can’t tell if you got it right until it dries. When it goes on, it’s cold and wet like paste. But as it dries, the Christmas magic kicks in and it puffs up, turning into fluffy white (or, in this case, purple) fuzz firmly affixed to the needles.

There are, of course, pitfalls. Not enough water, and the flocking falls off and makes a huge mess. A flocked tree can’t get wet a second time. “It won’t dry again. It’s disgusting actually,” Iantosca says. Also, when you flock a tree, the color highlights its flaws. A janky tree turns into a weird, uneven shrub.

But if you get it right and string it up with lights, you’ve got a real stunner on your hands. Iantosca’s had flocked trees for his own home for the past 10 years and his kids won’t let him go back.

“When you plug that thing in, it absolutely glows inside," he says. "It’s unbelievable.”

Have you got a Big Question you'd like us to answer? If so, let us know by emailing us at bigquestions@mentalfloss.com.

Why Do Fruitcakes Last So Long?

iStock
iStock

Fruitcake is a shelf-stable food unlike any other. One Ohio family has kept the same fruitcake uneaten (except for periodic taste tests) since it was baked in 1878. In Antarctica, a century-old fruitcake discovered in artifacts left by explorer Robert Falcon Scott’s 1910 expedition remains “almost edible,” according to the researchers who found it. So what is it that makes fruitcake so freakishly hardy?

It comes down to the ingredients. Fruitcake is notoriously dense. Unlike almost any other cake, it’s packed chock-full of already-preserved foods, like dried and candied nuts and fruit. All those dry ingredients don’t give microorganisms enough moisture to reproduce, as Ben Chapman, a food safety specialist at North Carolina State University, explained in 2014. That keeps bacteria from developing on the cake.

Oh, and the booze helps. A good fruitcake involves plenty of alcohol to help it stay shelf-stable for years on end. Immediately after a fruitcake cools, most bakers will wrap it in a cheesecloth soaked in liquor and store it in an airtight container. This keeps mold and yeast from developing on the surface. It also keeps the cake deliciously moist.

In fact, fruitcakes aren’t just capable of surviving unspoiled for months on end; some people contend they’re better that way. Fruitcake fans swear by the aging process, letting their cakes sit for months or even years at a stretch. Like what happens to a wine with age, this allows the tannins in the fruit to mellow, according to the Wisconsin bakery Swiss Colony, which has been selling fruitcakes since the 1960s. As it ages, it becomes even more flavorful, bringing out complex notes that a young fruitcake (or wine) lacks.

If you want your fruitcake to age gracefully, you’ll have to give it a little more hooch every once in a while. If you’re keeping it on the counter in advance of a holiday feast a few weeks away, the King Arthur Flour Company recommends unwrapping it and brushing it with whatever alcohol you’ve chosen (brandy and rum are popular choices) every few days. This is called “feeding” the cake, and should happen every week or so.

The aging process is built into our traditions around fruitcakes. In Great Britain, one wedding tradition calls for the bride and groom to save the top tier of a three-tier fruitcake to eat until the christening of the couple’s first child—presumably at least a year later, if not more.

Though true fruitcake aficionados argue over exactly how long you should be marinating your fruitcake in the fridge, The Spruce says that “it's generally recommended that soaked fruitcake should be consumed within two years.” Which isn't to say that the cake couldn’t last longer, as our century-old Antarctic fruitcake proves. Honestly, it would probably taste OK if you let it sit in brandy for a few days.

Have you got a Big Question you'd like us to answer? If so, let us know by emailing us at bigquestions@mentalfloss.com.

SECTIONS

arrow
LIVE SMARTER