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Yeasty treats to get you through the pandemic

by Leigh Krietsch Boerner
April 19, 2020 | A version of this story appeared in Volume 98, Issue 15


All you knead is loaf

A loaf for bread covered with poppy seed next to a knife on a board.
Credit: Sudeep Agarwala
This loaf is wild: A white-wheat-rye sourdough with poppy seeds on top that Sudeep Agarwala made with yeast he cultivated.

The stay-at-home orders enacted by most states in response to COVID-19 have bulldozed people into a new pastime: baking. Many are turning to bread, as it can be a great anxiety reliever to knead bread dough. But this bread-baking boom has had a definite downside: stores everywhere are out of baker’s yeast. You need yeast to make many kinds of bread because the single-celled fungi gobble up the sugars in the bread flour and spit out carbon dioxide, which makes the bread rise. But without yeast, what’s a quarantined baker to do? Yeast biologist Sudeep Agarwala blew Twitter’s collective mind in late March by posting a series of yeasty tweets.

An image of Sudeep Agarwala's first tweet about yeast.

There’s yeast on a lot of stuff, Agarwala says, and it doesn’t just come from those little Fleischmann’s packets, which are filled with a single strain of a yeast species that has been selected for its uniformness and hardiness. Yeastless bakers can propagate their own wild cultures by using dried fruit, flour, water, warmth, and time.

To harness this microbial magic, get some dried fruit (fresh fruit can technically be used, Agarwala says, but you have to leave it unwashed, and he would not advise doing that with COVID-19 flying around). Put that fruit in a jar with 30–40 mL of water, and swirl it around. The water may cloud up as your yeast floats off the fruit. Add an equal mass of flour to this mixture. “And then you wait,” he says in the tweet. Keep your new little friends warm but not too hot, and in about 12 h, you should see bubbles. That’s your yeast digesting the flour. Once the paste in your jar loosens up, in 24–48 h, take a bit of the mix and add it to 30–40 mL of water, add flour, and repeat. It will bubble up again, but more quickly this time. And ta-da! You have yeast.

This wild yeast you’ve grown is a bit different from the yeast we’re used to buying, Agarwala tells Newscripts. “Wild yeast are sort of like the drama kids or the band kids in high school,” he says, noting that he was one of those kids. “You give them an assignment, and it will be turned in late, but they’ll come up with something spectacular.” It just takes a little more time and nurturing. He says industrial yeast, the kind sold for bread baking, is more like the football jocks. “They’ve been selected to be able to make the most carbon dioxide in the shortest amount of time possible.” Bread from wild yeast can be a bit of a toss-up, he says. “You don’t know exactly how these are going to behave compared to the little jocks of baking.” But the results can be more interesting. “I’m very happy to have the football jocks whenever I’m making challah every Friday,” he says. “But as a biologist, I think the wild fermentation is absolutely fascinating.”

This Newscriptster tried cultivating yeast from raisins and dried mangoes, but it turned out . . . less than well. But Agarwala says not to give up. And if readers try this, let us know, and tweet at @shoelaces3 with pictures of your finished loaves because Agarwala wants to see them. “It’s lovely to see people who don’t think about yeast engaging with the world that I love and think so deeply about,” he says.


Doc Fauci doughnuts

An image of four doughnuts showing Anthony Fauci's picture on the top, surrounded by whipped cream with red, white, and blue sprinkles on top.
Credit: Donuts Delite/Facebook
Yeasty yummies: A to-go box of Doc donuts from Donuts Delite in Rochester, New York.

If you like your yeasty treats a bit sweeter, and you’re sweet on a certain head of the National Institute of Allergy and Infectious Diseases, we’ve got some news for you. Doughnuts with Anthony Fauci’s likeness are popping up at bakeries, mostly on the East Coast. During the COVID-19 pandemic, Fauci has become a trusted source of information in a scary time, picking up a national fan club. So perhaps it’s not a huge surprise that his visage has been enshrined in pastry.

For Fauci lovers craving a tasty tribute, Donuts Delite in Rochester, New York, will ship four packs of its “Doc donuts” within the US, but potential customers do have to call. And please remember to wash your hands before feasting on your Fauci.

Leigh Krietsch Boerner wrote this week’s column. Please send comments and suggestions to


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