The Reason You Shouldn't Throw Out Leftover Sourdough Starter
Baking your own bread has been steadily gaining popularity, with Refinery29 noting that, while searches for all bread recipes generally increase around the holidays, more and more people have been looking into making sourdough bread specifically and consistently throughout the year. They assert that the demand is so high that some smaller local bakeries have even begun to sell their own sourdough starters and sourdough kits in addition to the standard fully baked loaves and pastries.
Making your own sourdough can be an incredibly fulfilling and fun project, but it's known for being a fairly time-consuming and semi-complicated process — not to mention that once you get your starter going strong, you also have to keep it alive. The Kitchn suggests this routine care amounts to regularly feeding and discarding portions of the starter, which can feel wasteful for many who are not able to devote the time to baking a whole loaf each day. Many people new to baking sourdough bread do not realize that there are many ways to use up the discarded starter, which reduces kitchen waste and offers a break from bread.
How to use sourdough starter discard in almost any recipe
The Kitchn offers a pretty simple math equation to figure out how to use your sourdough starter discard in almost any recipe that calls for flour. The way you figure this out is by weighing your starter discard on a kitchen scale, then dividing that number in half. Since sourdough starter is half water and half flour, you can now subtract the half weight number you determined through your easy equation from both the flour and liquid measurements listed in your recipe's ingredients list.
Just follow the instructions normally, but use the new, lower measurements of liquid and flour, plus the sourdough starter discard. The Kitchn states that it does not really matter which step you add the discard in during the recipe. They recommend beginning with an easy recipe, like pizza dough or blueberry muffins, to get you started on your waste-free sourdough journey.
True Sourdough says you are also able to freeze or refrigerate sourdough discard, giving you time to collect enough for a specific recipe or project, or to just allow you to take a break from cooking and baking without throwing any starter away. They note that sourdough starter will keep for a few months in the fridge or up to a year in the freezer before it goes bad.