With the cold weather these days, one pandemic trend is continuing to warm people’s homes: sourdough baking. The process of making a loaf with live fermented cultures has risen in popularity since last March—largely because the yeast shortage early in the COVID-19 pandemic took other breads off the table, and because many people are spending more time at home, according to Benjamin Wolfe, who studies microbial ecology and evolution in his lab at Tufts. (See "Nine Tips to Make Sourdough.") “It’s really great during stressful times—it’s sort of like a creature, and you’re taking care of it. It’s a fun distraction, and if you get great bread, all the better,” said Wolfe, who recently published a paper on the varieties of microbes in sourdough starters in the journal