I work a lot with hungry and homeless kids, so there is naturally a desire to see big changes in their lives quickly. This weekend, though, I was reminded that there is a lot of power in small changes, too. Thanks to the Bread Baker’s Guild of America, I had an incredible opportunity to study the Science of Sourdough with Karen Bornarth (from the amazing Hot Bread Kitchen) and Debra Wink (a microbiologist and baker whose writings I have admired on The Fresh Loaf) at Companion Baking Company’s Teaching Kitchen here in St. Louis. We learned about metabolic pathways, which map the step by step transformations that allow an organism to turn one thing into another through chemical changes over time. I will admit that I did not completely master the chemistry of heterolactic fermentation and five carbon (or was it six carbon?) sugars, but I did get this: the changes are incremental and small things make a big difference. Karen and Debra pointed out again and again that adding a bit more water, a pinch of salt, a degree of temperature or an hour of time changes the nature of our treasured sourdough starters.
Where the sourdough starter is from does not matter nearly as much as how that starter is treated. The sourdough starter in my bakery originated in the bakery at King Arthur Flour, but now, ten years later, it’s chemistry is more about how it has been treated in my kitchen than how it began in theirs. My starter lives in the refrigerator during the week, and comes back to life through a series of feedings at room temperature on the weekends. Even though I bake with whole grains, I feed my starter with bread flour. I keep it liquid, at about 125% hydration, and never add salt, though I now understand why that would change things a bit too. A couple years ago, the quality of my starter was radically improved when James MacGuire kindly insisted that I never “put it to bed hungry” after a weekend of baking, but instead feed it right before I put it back into the refrigerator for the week. Adding 50 grams of flour to the 600 grams of starter I “put to bed” each Sunday night helps it wake up ready to go to work again on Friday mornings.
The Science of Sourdough helped me to understand why. Every starter has a lag phase as it begins to wake up after a feeding, a growth phase when the population increases, and a stationary phase when it rests again. As long as we feed our starters regularly they should never enter the dreaded “death phase.” Debra pointed out that starters go into the resting phase to conserve their energy, and the longer the starter rests -the longer it has to shut down in between feedings – the longer it takes to wake up and get back to the business of growing. This is where small changes can make a big difference. Feeding my starter one more time after baking for the weekend helps it to wake up stronger. Warming it up on Friday afternoons helps it come back to life faster. The bread flour feeding favors the yeast production that helps my bread lift, while the higher hydration favors the lactic acid production that adds the distinctive sourdough taste. Everything is a balance. There are a myriad of known and unknown factors that influence the taste and performance of each baker’s starter, and each one of them matters. That’s why every starter is unique, regardless of it’s point of origin.
I think kids are the same. There are a myriad of known and unknown factors that influence them and make them unique. How we feed them matters. It changes them. Food. Time. A warm place to rest and grow. These are not small things. They have the power to change people just as powerfully as they change bread. I think that’s what I love about baking and sharing – small changes can be transformative. As we learned this weekend, “the living element is very dynamic, and you have far more power to influence it than you may realize.” Many thanks to Debra and Karen for helping me to understand why.