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 Causes Red Tides?

William West/AFP/Getty Images
William West/AFP/Getty Images

Every once in a while, the ocean turns the color of blood and scores of dead fish rise to the surface. The phenomenon might look like a biblical plague, but the source is far more mundane. It's just algae.

Red tides occur when there’s a sudden population boom among specific kinds of algae, which in enormous quantities become visible to the naked eye. They occur all over the world. In the Gulf of Mexico, the culprit behind red tides washing onto coastlines from Texas to Florida is usually a type of microscopic algae called Karenia brevis. It produces toxic chemicals that can cause symptoms ranging from sneezing and eye irritation to disorientation, vomiting, and breathing difficulties. It's often fatal for fish, shellfish, turtles, and other wildlife.

The water appears red because of the particular depth at which the algae live. Light waves don’t penetrate seawater evenly, and certain wavelengths travel farther than others. The algae that cause red tides grow at depths that absorb green and blue frequencies of light and reflect red ones.

Not all algal blooms are red; some are blue, green, brown, or even purple. Nor do all algae harm humans or animals. Why and how certain species of algae multiply like crazy and wipe out entire swaths of marine life is still a scientific mystery.

The worst red tide on record occurred in 1946, when a mass of algae stretching for 150 miles along the Florida coastline killed more than 50 million fish, along with hundreds of dolphins and sea turtles. Tourists shied away from the beaches as the bodies of dead sea creatures washed ashore. Smaller incidents are more common, but just as costly. In the past decade alone, fishing and tourism industries in the United States have had an estimated $1 billion in losses due to red tides—and the cost is expected to rise.

Editor's note: This story, which originally ran in 2015, was updated in August 2018.

Why Do So Many Diners Look Like Train Cars?

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iStock

No matter how many fine dining options you may have in your area, there’s something about sitting down in a diner that can’t be matched. Their menus are models of American comfort food, from meatloaf to patty melts. The coffee cups are bottomless. There’s usually a toothpick dispensary at the register.

Many diners across the country have one additional identifying trait: They’re shaped like a train car, a sleek and narrow compartment that looks like it belongs on a set of tracks. When and why did this style choice become synonymous with diners?

In a piece for Atlas Obscura, Anne Ewbank shed some light on the practice. The early 20th century saw a rise in entrepreneurs who were interested in meeting the need for casual dining establishments for people hurrying to or from work. Their ambitions had evolved from the lunch wagons of the late 1800s, which provided shelter from weather by putting up awnings or letting people sit inside on stools.

City ordinances, however, made such operations a little tricky: Many food wagons needed to be permanent fixtures in order to avoid the narrow operating hours mandated by communities. Rather than hire a contractor or lease an existing commercial space, people opted to order prefabricated, mobile carts that could be shipped to their location by rail or towed by truck. These dining cars became known as “diners.”

Like the pop-up locations of today, the diners could appear virtually overnight. Most were delivered in one piece; others were modular, requiring minimal assembly, and could offer a greater variety of styles and seating capacities. For small business owners, their affordability and convenience made it possible to strike out on their own. Some manufacturers even offered to repair fixtures by having the diner shipped back to the factory.

The look became so intertwined with fast-dining that some owners recycled old train cars to capture the aesthetic. Today, even diners built from scratch often mimic the narrow, elongated shape so familiar to patrons—a design now borne out of choice rather than necessity. It's a curious bit of history, and one worth pondering the next time you grab a toothpick.

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