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Citizen science for sourdough and synchrotrons

by Megha Satyanarayana
June 21, 2020 | A version of this story appeared in Volume 98, Issue 24


A sour start

A jar containing sourdough starter.
Credit: Lauren Nichols
Wild things: A public science project at NC State hopes to catalog the microbes in wild-cultured sourdough starters.

During this coronavirus pandemic, many people have turned to baking to soothe frayed nerves or to pass a few hours while the kids Zoom their way through school work. A favorite of some bakers has been sourdough, a bread that typically relies on a starter culture of flour, water, and yeast to foment the ferment.

At the Public Science Lab at North Carolina State University, Rob Dunn, Anne Madden, and colleagues want to know what goes into your dough. Through a citizen science initiative called the Wild Sourdough Project, these researchers will analyze wild sourdough starters from all over the US to learn about the different yeast and bacteria that live in flour and how the communities the bugs build create the distinctive tastes of this variety of bread.

“There’s evidence that microbes that end up in our starters can originate from flour—what flour you use might impact what species you see, which might impact what flavors or aromas you have,” Madden tells Newscripts.

The lab leads volunteers through a 10-day protocol, adding flour and water together and watching as it starts to bubble and grow. Participants can use different flours, place their starter inside or outside and, at periodic intervals, record what’s happening in their primordial soups through questionnaires on the project website.

The focus on flour isn’t just about the microbes, Madden says. Different flours provide different nutrients to the bacteria and yeast that come along for the ride, and as those nutrients are metabolized, the by-products are the compounds that give sourdough its smell and taste.

“These microbes are generating a number of molecules, and many of those molecules we register as different aromas,” Madden says, referring to lactic acid and acetic acid, which give sour taste to the bread; phenylethyl alcohol and ethyl hexanoate, which give fruity and floral smells; and dextrans, which improve bread texture.

The use of fermentation in bread making is global, she says and not just limited to wheat flour. In Ethiopia, a grain called teff is wild fermented to make injera, a spongy flatbread. In India, rice and lentils are wild fermented to make a crepe called dosa. Someday, Madden says, the lab would love to catalog the microbial machines that make these staples as well.


Board at home

An image of a science board game.
Credit: Claire Murray
Game on: A new board game allows families to experience science as it works in real life.

Whether citizen or salaried, science is a collaborative venture, yet far too many people still think of discovery as the bastion of the lone researcher. Enter Diamond: The Game, a joint project of scientists at the University of Cambridge and Diamond Light Source, the UK’s national synchrotron.

In this print-at-home board game, you work your way through the synchrotron, designing experiments, finding collaborators, succeeding or failing, much the way you do in real life and in real science, says Claire Murray, one of the three creators of the adventure.

She and Mark Basham, both of Diamond Light Source, and Matthew Dunstan of the University of Cambridge, built the game as a way of helping young high schoolers in the UK understand what goes into scientific careers. It’s a labor of love that has taken about 3 years.

“To show that science is interdisciplinary,” Murray tells Newscripts, “you need chemistry plus physics, or chemistry plus biology, or maybe earth sciences plus biology—different mixes of things that actually contribute to solving an awful lot of problems.”

They tested the game with more than 200 students, most of whom came to Diamond on school field trips. Murray says many of the students were stunned to learn that failure is common in science, and that collaboration is vital.

The game was originally intended to be a traditional board game, and the team has received a grant to produce it as such for schools. But, as many families are still at home navigating the changing coronavirus pandemic, Murray says the printable version allows them a chance to experience science from the comfort of their living rooms.

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