In every episode of our podcast Things Bakers Know , we answer baking questions from our listeners. In our recent episode all about focaccia, one caller asked a very important question: How do I get a more open crumb in my focaccia? Below is an edited excerpt from hosts David Tamarkin and Jessica Battilana. You can find the full episode here . Jessica:  I think some of this comes down to the formula.You want to look for a recipe that's a higher hydration recipe. And I know that there are probably some listeners out there that are like, "Well, how do I know?" And you have to do math.…