If Beer and Bread Use Almost the Exact Same Ingredients, Why Isn't Bread Alcoholic?

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If beer and bread use almost the exact same ingredients (minus hops) why isn't bread alcoholic?

Josh Velson:

All yeast breads contain some amount of alcohol. Have you ever smelled a rising loaf of bread or, better yet, smelled the air underneath dough that has been covered while rising? It smells really boozy. And that sweet smell that fresh-baked bread has under the yeast and nutty Maillard reaction notes? Alcohol.

However, during the baking process, most of the alcohol in the dough evaporates into the atmosphere. This is basically the same thing that happens to much of the water in the dough as well. And it’s long been known that bread contains residual alcohol—up to 1.9 percent of it. In the 1920s, the American Chemical Society even had a set of experimenters report on it.

Anecdotally, I’ve also accidentally made really boozy bread by letting a white bread dough rise for too long. The end result was that not enough of the alcohol boiled off, and the darned thing tasted like alcohol. You can also taste alcohol in the doughy bits of underbaked white bread, which I categorically do not recommend you try making.

Putting on my industrial biochemistry hat here, many [people] claim that alcohol is only the product of a “starvation process” on yeast once they run out of oxygen. That’s wrong.

The most common brewers and bread yeasts, of the Saccharomyces genus (and some of the Brettanomyces genus, also used to produce beer), will produce alcohol in both a beer wort
and in bread dough immediately, regardless of aeration. This is actually a surprising result, as it runs counter to what is most efficient for the cell (and, incidentally, the simplistic version of yeast biology that is often taught to home brewers). The expectation would be that the cell would perform aerobic respiration (full conversion of sugar and oxygen to carbon dioxide and water) until oxygen runs out, and only then revert to alcoholic fermentation, which runs without oxygen but produces less energy.

Instead, if a Saccharomyces yeast finds itself in a high-sugar environment, regardless of the presence of air it will start producing ethanol, shunting sugar into the anaerobic respiration pathway while still running the aerobic process in parallel. This phenomenon is known as the Crabtree effect, and is speculated to be an adaptation to suppress competing organisms
in the high-sugar environment because ethanol has antiseptic properties that yeasts are tolerant to but competitors are not. It’s a quirk of Saccharomyces biology that you basically only learn about if you spent a long time doing way too much yeast cell culture … like me.

This post originally appeared on Quora. Click here to view.

What Happened to the Physical Copy of Martin Luther King's 'I Have a Dream' Speech?

AFP, Getty Images
AFP, Getty Images

On August 28, 1963, Martin Luther King Jr. stood on the steps of the Lincoln Memorial and gave a speech for the ages, delivering the oratorical masterpiece "I Have a Dream" to nearly 250,000 people.

When he was done, King stepped away from the podium, folded his speech, and found himself standing in front of George Raveling, a former Villanova basketball player who, along with his friend Warren Wilson, had been asked to provide extra security around Dr. King while he was speaking. "We were both tall, gangly guys," Raveling told TIME in 2003. "We didn't know what we were doing but we certainly made for a good appearance."

Moved by the speech, Raveling saw the folded papers in King’s hands and asked if he could have them. King gave the young volunteer the speech without hesitation, and that was that.

“At no time do I remember thinking, ‘Wow, we got this historic document,’” Raveling told Sports Illustrated in 2015. Not realizing he was holding what would become an important piece of history in his hands, Raveling went home and stuck the three sheets of paper into a Harry Truman biography for safekeeping. They sat there for nearly two decades while Raveling developed an impressive career coaching NCAA men’s basketball.

In 1984, he had recently taken over as the head coach at the University of Iowa and was chatting with Bob Denney of the Cedar Rapids Gazette when Denney brought up the March on Washington. That's when Raveling dropped the bomb: “You know, I’ve got a copy of that speech," he said, and dug it out of the Truman book. After writing an article about Raveling's connection, the reporter had the speech professionally framed for the coach.

Though he displayed the framed speech in his house for a few years, Raveling began to realize the value of the piece and moved it to a bank vault in Los Angeles. Though he has received offers for King’s speech—one collector wanted to purchase the speech for $3 million in 2014—Raveling has turned them all down. He has been in talks with various museums and universities and hopes to put the speech on display in the future, but for now, he cherishes having it in his possession.

“That to me is something I’ll always be able to look back and say I was there,” Raveling said in the original Cedar Rapids Gazette article. “And not only out there in that arena of people, but to be within touching distance of him. That’s like when you’re 80 or 90 years old you can look back and say ‘I was in touching distance of Abraham Lincoln when he made the Gettysburg Address.’"

“I have no idea why I even asked him for the speech,” Raveling, now CEO of Coaching for Success, has said. “But I’m sure glad that I did.”

What is a Polar Vortex?

Edward Stojakovic, Flickr // CC BY 2.0
Edward Stojakovic, Flickr // CC BY 2.0

If you’ve turned on the news or stepped outside lately, you're familiar with the record-breaking cold that is blanketing a lot of North America. According to The Washington Post, a mass of bone-chilling air over Canada—a polar vortex—split into three parts at the beginning of 2019, and one is making its way to the eastern U.S. Polar vortexes can push frigid air straight from the arctic tundra into more temperate regions. But just what is this weather phenomenon?

How does a polar vortex form?

Polar vortexes are basically arctic hurricanes or cyclones. NASA defines them as “a whirling and persistent large area of low pressure, found typically over both North and South poles.” A winter phenomenon, vortexes develop as the sun sets over the pole and temperatures cool, and occur in the middle and upper troposphere and the stratosphere (roughly, between six and 31 miles above the Earth’s surface).

Where will a polar vortex hit?

In the Northern Hemisphere, the vortexes move in a counterclockwise direction. Typically, they dip down over Canada, but according to NBC News, polar vortexes can move into the contiguous U.S. due to warm weather over Greenland or Alaska—which forces denser cold air south—or other weather patterns.

Polar vortexes aren't rare—in fact, arctic winds do sometimes dip down into the eastern U.S.—but sometimes the sheer size of the area affected is much greater than normal.

How cold is a polar vortex?

So cold that frozen sharks have been known to wash up on Cape Cod beaches. So cold that animal keepers at the Calgary Zoo in Alberta, Canada once decided to bring its group of king penguins indoors for warmth (the species lives on islands north of Antarctica and the birds aren't used to extreme cold.) Even parts of Alabama and other regions in the Deep South have seen single-digit temperatures and wind chills below zero.

But thankfully, this type of arctic freeze doesn't stick around forever: Temperatures will gradually warm up.

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