My fridge has a continual real-estate drawback. The problem isn’t leftovers; it’s condiments. Jars and bottles have stuffed the door and brought over the principle cabinets. There’s so little room between the chili crisp, maple syrup, oyster sauce, gochujang, spicy mustard, a number of sorts of scorching sauce, and quite a few different condiments that I’ve began stacking containers. Squeezing in new objects is like concurrently enjoying Tetris and Jenga. And it’s all due to three little phrases on their labels: Refrigerate after opening.
However lots of the time, these directions appear complicated, if not simply pointless. Pickles are normally stored chilly after opening, however the entire level of pickling is preservation. The identical is true of fermented issues, similar to sauerkraut, kimchi, and sure scorching sauces. Ketchup bottles are a fixture of diner counters, and vessels of chili oil and soy sauce sit out on the tables at Chinese language eating places. So why should they take up worthwhile fridge area at house?
In the meantime, meals languish within the pantry once they would do higher within the fridge. Nuts develop an off-taste after just a few months; spices fade to mud in roughly the identical time span. Just lately, a bag of flaxseed I’d purchased only a few weeks earlier went rancid and started to odor like paint thinner. Lots of generally unrefrigerated meals may gain advantage from chilly storage, Kasiviswanathan Muthukumarappan, a refrigeration skilled at South Dakota State College, advised me. But maddeningly, they aren’t labeled as such, whereas many shelf-stable meals are refrigerated by default. The conventions of meals storage are filled with inconsistencies, losing not solely treasured fridge area however typically additionally meals itself.
Judging by a visit to the grocery retailer, there are two sorts of meals: fridge meals and pantry meals. Pasta and granola bars, for instance, are stored at room temperature, whereas recent meals similar to meat, dairy, and produce are stored chilly. A majority of these extremely perishable objects are outlined by the FDA as “temperature management for security” meals, and protecting them under 40 levels Fahrenheit slows the expansion of many dangerous microbes, which may trigger meals poisoning. Outdoors the fridge, pathogenic microbes develop quickly: Based on the U.S. Division of Agriculture, these meals shouldn’t be left unrefrigerated for even simply two hours.
However the binary—fridge meals and pantry meals—is simply too simplistic. Many condiments, for instance, exist in a murky center floor. Some mustards can sit out on a counter, whereas others are liable to mildew, Karen Schaich, a food-science professor at Rutgers College, advised me. Relishes, that are normally chopped pickled greens or fruits, also can develop mildew or yeast fermentation if not refrigerated. Partially, it comes right down to their sugar content material: Microbes don’t thrive in acidic circumstances, however they typically do like some sugar. A broad rule of thumb is that “extraordinarily tart or bitter” condiments are normally secure to depart on the counter, so long as they aren’t additionally candy, Schaich mentioned.
Correct meals storage simply can’t be boiled right down to a single query—to relax or to not chill?—as a result of the results of refrigeration are twofold. Past security, the fridge helps preserve a meals’s taste. It does this partially by slowing the expansion of spoilage microbes, which normally aren’t dangerous however produce revolting flavors and odors. The fridge additionally slows pure processes that degrade high quality. As soon as security is managed for, “chemistry takes over,” Schaich mentioned, referring to reactions that trigger meals to develop bizarre or gross flavors over months and even years.
The massive one is oxidation, which is chargeable for many foul odors, tastes, and textures in meals, similar to stale Cheerios and oil that smells like Play-Doh. It’s brought on by publicity to oxygen and accelerated by components together with time, moisture, micro organism, gentle, and, crucially, warmth. Refrigeration retains meals tasting recent by controlling for the latter. That’s why merchandise similar to Heinz ketchup and Kikkoman soy sauce have labels saying they need to be saved within the fridge: not for security, however for taste. Put them in your pantry, and so they’re unlikely to make you sick.
In relation to sustaining taste, one molecule is extra consequential than others. “It’s the fats that issues,” Muthukumarappan mentioned. Fatty meals—sure nuts similar to pecans and walnuts, some sorts of oil—oxidize and go rancid, normally creating bitter or bitter flavors and, typically, the tangy odor of metallic or the waxy considered one of crayons. It is smart to refrigerate peanut butter, and nuts normally, Muthukumarappan mentioned. Higher but, retailer them within the freezer if you happen to plan on protecting them for years. Grains are likewise susceptible to rancidity: Hemp seeds have a excessive oil content material and might oxidize inside months, and so can some sorts of flour, Schaich mentioned—particularly, whole-grain flours similar to rye and spelt. Storing them within the fridge is healthier than within the cabinet, she mentioned, however vacuum-sealing them to take away oxygen, then placing them within the freezer, is greatest for long-term storage.
There are different causes you would possibly need to put issues within the fridge. Spices don’t normally grow to be rancid, however their efficiency fades. A milk-carton-size container of smoked paprika I ordered a few 12 months in the past is now principally crimson sawdust. Previous cumin smells uninteresting, like pencil shavings. The flavour and pungency of spices comes from unstable oils, which too are susceptible to oxidation. Staleness, Muthukumarappan advised me, is normally brought on by repeated publicity to the air—as in, recurrently opening and shutting a spice jar. Retaining spices close to warmth and lightweight can speed up the method. The freezer is beneficial if you happen to plan to retailer spices long run, offered that they’re stored in hermetic containers. But when they’re going for use steadily, it’s greatest for them to remain at room temperature. Retaining them chilly dangers condensation forming each time the container is opened, probably resulting in clumps, off-flavors, and even microbial progress, Luke LaBorde, a food-science professor at Penn State, advised me.
In all my years of cooking, I can’t bear in mind seeing a ketchup bottle that mentioned it was okay to retailer at room temperature, simply as I’ve by no means come throughout a spice jar that was meant to be stored within the freezer. Storage directions on meals, or lack thereof, manifest a unique actuality, one the place correct storage methods aren’t basic data however insider info: There most likely gained’t be any refrigeration directions on a bag of pine nuts, but when you understand, you understand. Anticipating each product to have detailed directions is unrealistic. A less complicated storage system, if a extra space-intensive one, may be to maintain every thing chilly by default. That method, at the very least most meals could be safer, and presumably keep brisker. Once I requested Muthukumarappan whether or not any meals would style higher if saved at room temperature, he mentioned he couldn’t consider any. But there’s nonetheless vigorous debate over whether or not tomatoes, bread, eggs, butter, and olive oil style greatest at room temperature.
The fridge-pantry dichotomy won’t ever totally embody the murky science of meals security, and the specialists don’t all the time agree. Even the principles for produce aren’t completely clear-cut: All sliced fruit, however not all complete fruit, ought to be stored chilly—particularly sliced melons. In contrast to most fruits, melons aren’t very acidic, making them extra hospitable to pathogenic microbes, LaBorde mentioned. Garlic is secure for a number of months when stored at room temperature, however do-it-yourself garlic-in-oil carries the chance of botulism except refrigerated.
There’s just one strategy to reclaim our fridge area and keep away from rancid nuts, stale oats, and moldy jellies: pondering past the fridge-pantry binary. Particularly, think about how lengthy and the place you plan on storing meals. It’s not all the time straightforward: Purchase in bulk from Costco, the place you may get a five-pound bag of walnuts and a gallon of mayonnaise, and meals can simply linger—or be forgotten—in a moist pantry for months, even years. Nonetheless, if a bottle of ketchup goes to get used up in per week of summer time barbecues, you possibly can let it hang around on the counter. Went nuts when the walnuts went on sale? Freeze some for future you.
The science of meals storage was broadly identified a number of generations in the past as a result of it was taught in American colleges, Schaich advised me. Now we’re on our personal. Though we’re unlikely to ever grasp all of its complexities, understanding it just a bit extra has some benefits. Disregarding the advice to refrigerate an open jar of capers gave me a frisson of pleasure—not simply because it felt like breaking an imperfect rule, however due to the area it opened up in my fridge.