The Clear Sign That Your Sourdough Starter Is Beyond Saving

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Figuring out how to make a sourdough starter at home can be tricky and takes a lot of patience. Beginners are most likely to make common mistakes that kill their sourdough starter, and like any other hobby with a learning curve, it's all part of the process. But for safety reasons — and to ensure your efforts aren't in vain — you should know the clear signs that your sourdough starter is beyond saving. Nathan Myhrvold, founder of Modernist Cuisine and co-author of "Modernist Bread at Home," spoke exclusively with Chowhound to help us figure out when it's time for a new batch instead. "If you ever see mold, pink or orange discoloration, or smell something truly rancid, that's a clear signal it's beyond saving," he told us. "At that point, the safest move is to discard it and start fresh."

On the flip side, a sign that your sourdough starter — also known as levain — is doing well is when it's bubbly and gives off a pleasantly tangy scent and a wheaty, sweet aroma. "You can also perform a float test by dropping a spoonful of levain into water," Myhrvold advised. "A mature sourdough starter will have enough carbon dioxide in it to float in liquid. If it can float, it can leaven your dough." Be careful, though — a starter may also give off signs that appear suspicious, and while it's not a lost cause, it will need to be revived.

Whether you're using the best flour for your sourdough starter or giving it as much attention as you would a pet, sometimes it will still show signs that it needs some extra love. A hooch, which is a cloudy liquid that can gather on top of your starter, might raise some flags, but it means you just need to feed it. Another telltale sign that you need to pay more attention to your sourdough starter is when it starts smelling too strong, kind of similar to nail polish remover. There are a lot of reasons why this could be, such as storing it in a place with a less-than-ideal temperature, forgetting to feed it, or feeding it too much. Fortunately, it only needs an easy tweak. "Start by fixing obvious problems, such as abnormal temperatures or your feeding schedule," Nathan Myhrvold recommended. "Insulated coolers are great for this. Some people use heating blankets on a low setting to keep their starters snug during cold spells."

And though it's quite similar to starting from scratch, Myhrvold told us, "Some bakers recommend reviving a sluggish levain with diastatic malt powder (0.5%), instant dry yeast (0.05%), Florapan (0.1%), or rye flour (10% to 20%; reduce the bread flour by the same amount)." Overall, checking to see what your sourdough starter needs in order to be revived can be a trial-and-error process, but the end result can lead to something glorious.