How To Tell If Your Bread Is About To Go Bad

Whether you've put in the time and care of baking your own loaf of bread from scratch or you spent your hard-earned coin at the store on a loaf, there's nothing worse than pulling out some slices just to see spots of mold. It happens all too often, and all too soon, and while there are steps you can take to prolong your bread's lifespan, like proper storage, you can also keep your eyes peeled for some telltale warning signs. Think of these as alerts that tell you to use it up, freeze it, or plan to make a batch of French toast — and fast — before the carbs have passed their prime. 

Nathan Myhrvold, founder of Modernist Cuisine and lead author of the Modernist Cuisine cookbook series, is an expert on all such things. He quite literally wrote the book (several actually) on bread — with his recent cookbook Modernist Bread at Home, among others. Myhrvold explains that even well-stored bread will of course go bad in a matter of days. But before it's too late and they have to be tossed, you can keep a sharp eye out for signs like moisture redistribution, he says — a fancy way of saying bread will start going either dry or soggy in certain areas as it nears the end. Aging loaves will also start going stale, which is different than just drying out, and a precursor of further aging.

Nathan Myhrvold knows his way around a good loaf of bread, and he's also an expert on spotting a loaf that's beginning to lose its luster. He points out moisture redistribution as a hallmark sign, and further explains that this means that the once-crispy crust becomes chewy as moisture moves around the loaf, or that the whole thing becomes dried out. Dry bread can still taste good — and sometimes it's even preferable (think croutons or bread pudding), but it's a clear sign decay has begun, and mold is around the corner. 

Stale bread, another sign of decay, is when it's dry and lacking moisture, has lost its bouncy, squishy feel, and begins to take on a brittle, crumbly texture. Not to mention it loses its fresh taste. This involves a whole different process involving chemical changes to the starches at a molecular level.

Keep an eye out for these precursors to a rotten loaf, as they're good indicators that it's time to use up the slices while you can. The final stage includes mold, and once you spot any, the gig is up and there's no coming back. Though we all want to reduce food waste, once bread is bad, it's bad. Consuming mold can be highly harmful and the USDA recommends tossing the entire loaf if you see mold even just on one piece.

Proper storage of bread is absolutely vital — lackadaisical storage attempts invite changes to moisture levels and thus rev up the aging process. This doesn't just mean keeping it on the countertop in its original bag with the plastic loosely wrapped up or folded over and hoping for the best. Nathan Myhrvold says plastic isn't the best thing to keep it in at all, as loaves sealed in plastic lose some of their water, creating a more humid environment inside the bag which encourages mold growth. Myhrvold suggests ditching the plastic bag it came in and keeping your fresh loaf covered. He suggests using breathable material instead — which, somewhat counterintuitively, actually slows down the redistribution of moisture. The freezer is a great choice if you've bought extra bread at the store or have more than you know you can use up any time soon (conversely, the fridge should be a last option for bread storage, so go straight to the freezer!)

Got a loaf you know the clock is ticking on? Don't toss that stale or dried-out bread, so long as it does not have mold spots yet, says Myhrvold. Give it a second life by making it into the perfect DIY croutons, your own breadcrumbs, or sweet treats like french toast or bread pudding, both of which are at their best and most delectable when made with less-than-fresh slices.