My fridge has a persistent real-estate drawback. The difficulty isn’t leftovers, however condiments. Jars and bottles have stuffed the door and brought over the primary 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 taking part in Tetris and Jenga. And it’s all due to three little phrases on their labels: refrigerate after opening.
However loads of the time, these directions appear complicated, if not simply pointless. Pickles are normally saved chilly after opening, however the entire level of pickling is preservation. The identical is true of fermented issues, comparable 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 precious fridge area at house?
In the meantime, meals languish within the pantry once they would do higher within the fridge. Nuts develop an off style after a couple of 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 scent like paint thinner. Loads of generally unrefrigerated meals may benefit from chilly storage, Kasiviswanathan Muthukumarappan, a refrigeration skilled at South Dakota State College, informed me. But maddeningly, they aren’t labeled as such, whereas so many shelf-stable meals are refrigerated by default. The conventions for meals storage are stuffed 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 saved at room temperature, whereas recent meals comparable to meat, dairy, and produce are saved chilly. Some 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 might trigger meals poisoning. Exterior the fridge, pathogenic microbes develop quickly: In response to 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 just too simplistic. Many condiments, for instance, exist in a murky center floor. Some mustards can sit out on a counter, whereas others are vulnerable to mould, Karen Schaich, a food-science professor at Rutgers College, informed me. Relishes, that are normally chopped pickled greens or fruits, may develop mould or yeast fermentation if not refrigerated. Partly, it comes right down to their sugar content material: Microbes don’t thrive in acidic situations, 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 sit back 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 partly 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 liable for many foul odors, tastes, and textures in meals, comparable 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 like 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, they usually’re unlikely to make you sick.
On the subject of sustaining taste, one molecule is extra consequential than others. “It’s the fats that issues,” Muthukumarappan mentioned. Fatty meals—sure nuts comparable to pecans and walnuts, some varieties of oil—oxidize and go rancid, normally creating bitter or bitter flavors and, typically, the tangy scent of metal or the waxy considered one of crayons. It is sensible to refrigerate peanut butter, and nuts typically, Muthukumarappan mentioned. Higher but, retailer them within the freezer when you plan on protecting them for years. Grains are likewise weak 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 comparable to rye and spelt. Storing them within the fridge is best than within the cabinet, she mentioned, however vacuum-sealing them to take away oxygen, then placing it within the freezer, is finest 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 yr in the past is now principally purple sawdust. Outdated cumin smells boring, like pencil shavings. The flavour and pungency of spices comes from unstable oils, which too are weak to oxidation. Staleness, Muthukumarappan mentioned, is normally brought on by repeated publicity to the air—as in, often opening and shutting a spice jar. Maintaining it close to warmth and light-weight can speed up the method. The freezer is beneficial when you plan to retailer spices long run, supplied that they’re saved in hermetic containers. But when they’re going for use steadily, it’s finest for them to remain at room temperature. Maintaining them chilly dangers condensation forming each time the container is opened, doubtlessly resulting in clumps, off flavors, and even microbial development, Luke LaBorde, a food-science professor at Penn State, informed me.
In all my years of cooking, I can’t keep 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 saved within the freezer. Storage directions on meals, or lack thereof, manifest a special actuality, one the place correct storage methods aren’t basic information however insider info: There in all probability received’t be any refrigeration directions on a bag of pine nuts, however if you recognize, you recognize. Anticipating each product to have detailed directions is unrealistic. An easier storage system, if a extra space-intensive one, is likely to be to maintain every thing chilly by default. That approach, at the very least most meals could be safer, and presumably keep more energizing. 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 may be nonetheless full of life debate over whether or not tomatoes, bread, eggs, butter, and olive oil style finest 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, needs to be saved 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 saved at room temperature, however home made garlic-in-oil carries the danger of botulism until refrigerated.
There’s just one option to reclaim our fridge area and keep away from rancid nuts, stale oats, and moldy jellies: pondering past the fridge-pantry binary. Particularly, consider 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 mayo, and meals can simply linger—or be forgotten—in a damp pantry for months, even years. Nonetheless, if a bottle of ketchup goes to get used up in every week of summer time barbecues, you’ll be able to 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 recognized a number of generations in the past as a result of it was taught in American faculties, Schaich informed 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.
