What’s the sitch with tactics to extend the shelf-life of perishables in your fridge?
This is a topic we receive frequent queries on, but have yet to fully explore. It is a delicate subject to broach, because many are frustrated by regularly throwing out food that has gone bad, but few feel there is anything they could have done differently to prevent such spoiling. They may even take offense to the suggestion. Many of those who acknowledge that their behavior (or lack there of) leads to more food waste feel that too much effort is required to escape this pattern, and that simply buying new food and empty trash bags is the less stressful option.
We are not here to say that the struggle isn’t real; that is never what we are about at whatsthesitch.com. We are here to delve into a sitch, and then offer common sense work-arounds that we have found helpful while navigating similar struggles.
First, some general principles. Maybe this is an obvious point, but we’ll make it anyway: food becomes inedible when bacteria or fungi are allowed to grow in and around it. These often single-celled organisms are not so different from you and I, in that they grow best when provided with the right balance of sugar, water and oxygen, at adequate temperatures. Refrigeration only modulates one of these factors, namely, temperature. The microorganisms that contribute to food spoilage, as a general rule, grow much more slowly at temperatures approaching the freezing point of water. Another factor to consider is that, while these primitive lifeforms are ubiquitous in the environment, they can be largely killed off by bringing food back to temperatures approaching the boiling point of water.
From an individual food’s perspective, be it a bunch of fresh vegetables or the leftovers from a large stew, the refrigerator is not an endpoint. It is one stop in a lifecycle. Think of it as a highway, with designated lanes for movement and exits, as opposed to a parking lot. It is easy to forget where you parked your car in a large mall lot, give up on it after a brief search, and go out to buy a new car the next day. In my youth I did this more frequently than I’d like to admit. It’s an expensive habit to maintain.
Taking the view of a whole refrigerator space, we are not talking only about individual foods all chilling in their own ice-boxes, or, to return to the previous analogy, all driving on their own roads. We are talking about an ecosystem, all existing in a delicate balance, interacting with each other’s scents, temperatures, and microbial inhabitants. This is a multitude of carsgoing different speeds, changing lanes, some exiting quickly, others on a cross-country road trip destined for adventure. We will not, nay, cannot conclude an analogy that still has application, regardless of how tiresome it may be (pun intended).
All of the basic tenets that follow are used in homes the world round, by people with better things to do than attempt to write a comprehensive piece describing them. In fact, I suspect, a more comprehensive article of this nature has already been written, more clearly, by those with more experience in the field. That said, you would have to go find those theoretical articles. And you're already reading this one. Our point is, these are not new theories, but they have been collected here, and we hope they help you in your battle with food preservation moving forward.
Fresh, crisp vegetables are foods that lose value relatively quickly, and therefore contribute to a significant portion of the waste we generate by mismanaging refrigeration. There is a range of shelf lives, from spinach to carrots, and we will not delve into each individually.
Raw vegetables come from the store, or the farmer’s market, covered in environmental contaminants, including bacteria, dirt, fertilizer and pesticides. Washing up-front will save you time and effort when it comes time to prepare a meal. That said, water on our refrigerated foods is best avoided when possible. So shake off or dry washed veggies briefly before packaging. I usually go as far as throwing a paper towel in with each group of veggies, in order to wick water off of their delicate surfaces as it is naturally exuded. Remember, vegetables are made mostly of water, and it will continue to surface as the veggies age, no matter if there is bacterial growth or not. This process is accelerated by salts or dressings (osmotic pressure across membranes and such), so keep that in mind when pre-seasoning.
Large plastic bags or tupperware are essential to vegetable shelf-life. Reducing available oxygen, as well as exchange of gases, retards bacterial growth further (again, they are not so different from us… imagine trying to grow with a sealed plastic bag on your head). I find storing spinach or other leafy greens, washed, in a large tupperware with a paper towel or two, significantly extends shelf life and ease of use versus leaving the delicate greens in the bag they came in, open to the environment, without a wicking device of any sort. This is also particularly relevant when thinking about fresh herbs. Wrap the whole bunch of cleaned herbs tightly in a paper towel before putting them in a plastic bag and rolling the air out; using an entire head of cilantro becomes less daunting when it can be accomplished over the course of a week, as opposed to three days. I also, personally, find ‘processing,’ up-front very valuable. This includes cutting the joined ends off of celery, cutting off the butts of carrots (and even cutting them into smaller carrots sticks for immediate enjoyment), or shredding a whole cabbage into a slaw-type situation. This extra processing step generally does not impact shelf-life directly, but can be the difference between conveniently using up the last veggies in the back of the fridge versus letting them sit there until they begin the downward spiral toward waste.
This leads us to a good example of leftover repurposing that we had intended on sharing when workshopping this sitch. Cabbage is a hearty veggie, which is also delicious raw. I like to make coleslaw for the whole office here at whatsthesitch.com on an almost weekly basis. This raw slaw typically can last 5-7 days no problem, particularly if you avoid a mayo-based dressing. The cabbage holds-up over this span, but by day 5 or 6 it can get a little bit wilted, and some fluid will have seeped out. I continue to drain any fluid along the way, and as the cabbage gets more uncomfortable to eat raw, I fry it in veggie stir-fries, and add it to soup or curries, etc. If there are leftovers from any of those meals, they go in the fridge and the cabbage clock starts again. It is harder to let slaw go bad than it is to find a good use for it.
*Importantly, many of these principles do not apply to vegetables that come with natural “wrappers,” including onions, potatoes, squash, and garlic (is this a vegetable?). Their attached skins provide adequate protection from the evils of water and oxygen, and they will last nicely on a cool, dark pantry shelf. I will add though, once the skin of an onion is broken, refrigerating the leftover half is wise.
Fruit also exists on a huge spectrum of post-growth lifespan, from strawberries to apples. Particularly when dealing with fruits it is important to realize that cool temperatures affect biochemical processes other than bacterial metabolism. In their natural environments fruits ripen on their plants systematically, using volatile chemical signals transmitted through air and branch. It is via these processes that fruits obtain their distinct aromas, flavors and colors. Some of this is interrupted when we pick the fruits, but, as you have experienced, the ripening continues to occur (due to production of gases by the fruits themselves). Natural ripening occurs at, you guessed it, natural temperatures, generally in that 55-75 degree range. Hotter than this range (as in some warm kitchens) fruits will ripen more quickly; cooler and they will proceed more slowly. The pace of ripening, and when within the process a fruit is eaten will directly affect its taste. Some fruits have a much narrower temperature range and timescale than others when it comes to achieving proper flavor.All this said, when attempting to extend the shelf-life of fruits, refrigeration does work. If you don’t have a picky palate, it is safe to refrigerate. In many cases, particularly with fruit that is largely done ripening by the time you buy it at the store (apples, citrus, melons, berries…), refrigeration can augment the refreshment provided by a burst of fruit juice during the first bite. Refrigeration can also alleviate stress associate with fruits that have small windows of “ideal fruitiness,” such as pears and peaches.
I will add, there is much debate over whether to refrigerate certain fruits, in particularly tomatoes (and bananas and avocados, to a lesser extent). This fruits are valued for their specific flavors and textures, induced by precise ripening, and can be negatively impacted by the low temperatures of refrigeration. Such gray areas of preservation versus flavor are best left up to the educated, experienced user. For the example of the noble tomato: if you have the wherewithal to buy a ripe, in-season tomato, perfectly formed and ready to enjoy, and then you put it in the fridge with the aim to extend it’s shelf-life… that’s on you bro. You gotta figure out your goals on the front end. Just eat the damn tomato.
Lastly, briefly, acidic agents can prevent browning caused by oxidation of sugars (or fats) on the surface of fruits. Squirting a little lemon juice on chopped apples or melons can reduce discoloration and mushiness, but only for a day or so. This also applies to an extra squirt of lime juice added to the surface of a bowl of guacamole you hope to store. While on this topic, continuing to provide ripening signals can also have a preservative effect on this most delicate flesh of avocados. Leaving a pit in the guacamole can trick the velvety green dip into thinking it is still held peacefully within the cocoon of its previously discarded leathery shell.
This is another misunderstood medium that we have struggled with here in whatsthesitch.com’s kitchen for many years. Like most foods, bread is best fresh. It can stay great for longer by keeping it in an airtight wrapper/container. This is the most important consideration when it comes to preventing the onset of staleness, or slightly later, mold. We could easily get off-track here on an in-depth look at types of breads, gluten, salt and sugar content, why some dry out more quickly than others, etc. We’ll leave that up to you.
The basics are, store bread at room temperature. At the first hint of staleness, cut it into slices and freeze it in an airtight bag. Then retrieve a piece when you want and toast it back to life. Refrigeration has no role to play in bread storage. It actually makes bread go stale more quickly than tabletop storage, as lower temperature reduces the water-binding potential of bread-tissue. Freezing does not have the same effect, as it halts all fluid movement. With that in mind, there is never a situation where bread refrigeration is appropriate. A loaf of breadcan be tough to get through while leaving it on the counter, particularly in this post-Atkins diet world we live in. I highly recommend freezing bread when necessary; it comes out of the toaster without any hint of its old age.
If you are wary of eating bread after it has been frozen (for whatever misguided reason), once it is starting to stale, fry hunks of it in olive oil to make some nice croutons, or toast it thoroughly and blend it into bread crumbs (both of which freeze very nicely).
Grains and Legumes:
Now we are getting into more user-friendly categories. Grains and legumes (i.e. rice and beans) are hearty foods that lose very little in terms of texture and flavor when refrigerated. These are two very distinct groups of edibles, but will be discussed together because the approach to their refrigeration is so similar. Of note, like bread, other grains will dry out with refrigeration (including rice and pasta). But this doesn’t have to be a bad thing, and will exemplify the concept that refrigeration is but one step in the life cycle of a food, particularly the hearty ones.
Fried rice can really only be made properly with leftover rice, that has dried out somewhat. In this way, the potent little grains do not stick to each other, and are available to soak up the flavors of garlic, ginger, soy, etc. that they are fried in on the second go ‘round. If you’ve ever tried to make fried rice with fresh, hot, white rice, you’ll recall that it all stuck together and to the bottom of the pan, and was not the same as the dish you get from your local fried rice purveyor.
In similar fashion, refried beans are called refried beans because they have been refried. Why would one refry something that is already fresh and hot? This is an example of a traditional food based solely on the concept of repurposing leftovers. Beans are stewed one day and enjoyed with tortillas. The next day they are fried and enjoyed again, slightly more mushy. They next day they are mashed, and then REFRIED in lard, to be enjoyed once more. The bean has evolved as a food during its repeated refrigeration and heating cycles, rather than devolved. Intesting.
Additionally, leftover grains/legumes are perfect fillers for hearty fall stew. A week after cooking that barley, when you are increasingly worried it will not make for an enjoyable dinning experience… throw it in a pot of flavorful boiling water! Any small microbial growths that have taken root will quickly meet their steamy doom, with you none the wiser about their existence. (That said, if something is rotten, don’t put it in soup… we are talking about older leftovers, but not containers with a distinctly rancid odor. If you ruin your soup because ofour advice, you’re not reading carefully enough, and you’re too easily influenced by silly internet articles.)
Meat is expensive, delicious, and only exists because an animal was slaughtered. Keeping those factors in mind, one should always try to eat their meat-based leftovers relatively quickly. No reason to let them sit around. As with the other categories, there is a range of degradation rates for the different animal’s flesh, from fish to steak, and everything in between. Generally, meat will not last much longer than a week before getting weird. Eat it up, no other solution. One principle that applies here is surface area to volume ratio and it’s impact on a food’s vulnerability to microbial colonization. Small pieces of chicken likely won’t last as long as an intact breast, and the same applies to steak, etc.
Preserved or smoked meats, such as salami, bacon, or lox, warrant their own discussion. Needless to say, they are “preserved,” and therefore last longer than raw, or cooked meat.
Dairy is a classic perishable, coming out of the cow (or other mammals’) tit as a ready-made bacteria growing medium. We’ve all heard of rotten milk. Yogurt, by definition, is full of living microorganisms. It is sometimes desirable for cheese to be covered in mold, other times not so much, but the point stands; these lactose-based, fat and protein-laden slurries are perfect homes for unicellular food-ruiners.
The key term here is inoculation. Dairy will last plenty long if the only microbes that come in contact with it have to float through the air to reach the growth medium. But the minute you put the spoon from your mouth back into the yogurt, or drink directly from the milk jug, or handle the exposed cheese more than necessary, or double dip your saliva laden carrot into the sour-cream-based spread, boom. You’ve gotten your disgusting human microfauna/flora into the pasteurized nutrient bath, and the clock is ticking. This is true for all leftovers, but is particularly essential to avoid with dairy. Inoculation can also occur just by letting dairy warm to room temperature while exposed to air, before cooling it in the refrigerator again. A few bacteria in your kitchen will settle into the comfortable, warm dairy before you close off access, and there they will remain, growing slowly, insidiously, in your fridge.
Maybe you regularly inoculate your dairy products, but you also happen eat/drink them fast enough to never have noticed spoilage; then I suppose this advice isn’t for you. But you are playing a dangerous game my friend. And don’t say you weren’t warned. Your time is nigh.Jarred Items:
This is a category worthy of mention, but again, one that would require a whole recipe book to fully explore. Canning or jarring items obviously extends their shelf-life astronomically, when done in the traditional way. Refrigeration isn’t even required until after the sterilized jar has been opened, exposing its contents to the environment. High concentrations of salt, sugar or acid (vinegar) also prevent bacterial growth, preserving foods that are amenable to soaking up said ions. There are more casual ways to put these tools to use as well. Refrigerator pickles are a great, quick way to preserve otherwise finicky vegetables, such as pickles or green beans or mushrooms or asparagus. This does not need to be more complicated than boiling them quickly in a salt/sugar/vinegar bath, putting them in jars while hot, letting them cool to around room temperature (to avoid increasing fridge temperature and encouraging growth on surrounding leftovers… think ecosystem!!!). Often, if you plan to eat these quick pickles quickly, the boiling step can be skipped altogether.
As our long time readers know, we have to briefly touch on the sitch with peanut butter whenever possible, and it can generally be considered a jarred item. It is barely worth mention in the context of extending shelf-life via refrigeration, because it lasts so dang long with or without chilling. Sometimes refrigeration can make it hard to spread on bread. I usually avoid it, unless the label explicitly tells me to, like some of the natural kinds (and even those do fine without refrigeration for a week or more). That’s all. We love peanut butter here in the whatsthesitch.com offices.
We’ve gone over many different individual food categories and how to extend their edibility. The practice gets more complicated when thinking about preserving combinations of ingredients coming from multiple categories. You have to approach each as an individual case; fried rice with carrots and onions has a very different fridge trajectory than, say, a yogurt-based chicken curry. One good rule of thumb is, your mixture is only as edible as its most perishable item. So think about what within the concoction is most susceptible, and focus on the principles for preventing that spoilage.
Another way of thinking, that can be used in parallel, is that of liquid producers vs. absorbers. If there are diced tomatoes in a dish, they will drain some liquid over the course of their fridge time. If combined with a grain, known to absorb that liquid, you likely will be able to delay the sauce-pooling effect, and therefore delay spoilage. This isn’t something you would have to worry about if this was corn in the same grain dish. Likewise, if the tomatoes were combined with mushrooms and asparagus (perhaps after a grill sesh of sorts) then you may have toworry more about moisture developing over the course of a few days, as their are no absorbers involved. Maybe add those leftover veggies right atop the quinoa you already had refrigerating, depending on your shelf-life goals for all of the above. You can see how tough some of these decisions become as soon as mixing enters the conversation.
Lastly, as mentioned before, the fridge is a temperature-regulated ecosystem. So before placing a fresh, piping hot mixture on top of your vegetable drawer, next to your milk, remember, that heat will spread…
Refrigerator architecture is a creative science unto itself. It is particularly important to have a basic understanding of this when living in a household where not all of the food is shared. I won’t delve much into the applicable principles of refrigerator architecture, but will say, a well-organized refrigerator can significantly reduce food spoilage and waste. This is due to decreased rates of ‘transient refrigerator blindness.’ This, of course, is when a person temporarily loses their vision when looking in a refrigerator. There are a variety of theories as to the pathophysiology underlying these episodes, from the cold temperatures temporarily shocking the retina to the difficulty our brains have recognizing various sized boxes within other larger boxes. There is still much research to be done. We do know a clean, properly arranged fridge, with all items accounted for, can largely prevent the onset of refrigerator blindness until a much older age, when actual blindness starts to set in.
As in many human behaviors involving a group working toward a common goal (in this case food preservation), strong leadership can be the difference between success (eating well) and utter failure (food poisoning). Known as the “Fridge Captain,” this person surveys the fridge on a regular basis, assessing how long items have been on the shelves, and given the estimated lifespans, decides on timeframes for when each should be used by, and furthermore, coherent meals that can be made from the ingredients that need using. For experienced captains, this can all be done in his (or her) head, and, once they have an idea of the fridge contents for a week or so, can be done from outside the home. This is more of a way of life than it is a job that you punch in and out of.
A fridge captain will forgo a dinner out with friends because they are aware of the mashed potatoes and hard-boiled egg in the fridge at home, both approaching ruin. A fridge captain, despite their urge to eat cereal, will have that last piece of almost stale toast for breakfast instead. Are brussel sprouts a good side for linguini and meatballs? They can be, if there is afridge captain present. Fridge captainship is about sacrifice for the greater good, it is about controlling impulses, and it is about making the hard decisions when no one else is willing to.
Food life extension using refrigeration technology is a practice that has been around for millennia. For much of this history, past societies relied on harvesting ice for its inherent cooling properties (it being cold as shit). Since the advent of electricity and the installation of powerful refrigerators in most homes, we all now have more control over the temperature of our food than ever before. And yet, we ignore this great power, allowing food to spoil regularly, while it sits within reach on the shelves of our brightly-lit cooling-computers.
We here at whatsthesitch.com urge you all to go home tonight, and look at your refrigerator. Go ahead. Look at the outside of it for a good 5-10 minutes. Ponder its historical context, its function, the space it occupies in your home. Appreciate its contours. Caress its smooth exterior. Grasp its handle. Open the door. And never look back.