46: That’s the number of known descendants of “Herman,” a sourdough starter. Starter is the fermented mixture of water and flour that gives the bread its distinctive flavor. To use it, you divide it, putting one part back in the fridge; the other part goes into a batch of fresh dough — or into the hands of other bakers. Some starters have been kept alive for more than a century. Gabriel Leventhal created the Herman Project at MIT to crowdsource information on how microbial communities change as starter makes its way around the world. Herman started in the summer of 2016 with nine direct offspring. Each of Herman’s descendants get a unique name and number. Bakers return samples to the lab to track how the microbes evolve.