Heather and Joanne are off this week, so we’re showcasing an episode from another Vox Media Podcast Network show: “The Milk of Life,” from Gastropod. On Gastropod, hosts Cynthia Graber and Nicola Twilley explore the history and science behind everyday foods. Past episodes have examined everything from the evolution of the cookie to the surprising impact the coffee bean has had on world history. In this installment, originally aired on June 21st, Cynthia and Nicola use the ongoing baby formula shortage as inspiration for a wide-ranging investigation of the origins and development of formula.  Heather and Joanne will be back next Tuesday with a brand new episode of Now & Then, which will focus on how the missing Secret Service records from the days before January 6 evoke other political mysteries from American history.  In the meantime, enjoy this episode of the Gastropod podcast. And if you like it, you can find more episodes of Gastropod at link.chtbl.com/Gastropod. New episodes drop every other Tuesday. For a transcript and show notes for “The Milk of Life,” head to gastropod.com/the-milk-of-life Learn more about your ad choices. Visit podcastchoices.com/adchoices