Tag Archives: Refrigerator

How does an air conditioner work?

A seemingly humble and common device, the air conditioning is in fact the result of crafty engineering. It cleverly uses the laws of physics to move heat from one place to another — out of your house, usually. But as we’ll soon see, there’s no joking around with the laws of physics. It’s a complex topic, so let’s dive in and see how we bend physics to our will for our comfort and safety by squeezing and pumping some strange chemicals around in some pipes.

Image via Pixabay.

Keeping things cool isn’t useful just in social situations. In fact, a lot of what we consider to be the modern way of life is only possible because we’ve learned how to make hot things cold. Between 1998 and 2017, for example, more than 166,000 people died due to heatwaves, according to the WHO. Cold conditions seem to be the deadlier overall, as one study reported that between 2011 and 2018 “hypothermia made up 27.0% of all temperature injuries, but 94.0% of all deaths”.

Temperatures can pose a threat through more than just direct exposure. Improper refrigeration of items such as food or medicine can cause them to spoil, leading to financial losses or adverse health effects. Finally, much of our technology needs to be kept within certain temperature ranges to function properly — this includes your laptop, space telescopes, and nuclear reactors.

To understand how we’ve managed to get a grip on temperature control, let’s first start with the basics.

What is ‘temperature’?

Temperature is how we measure how much thermal energy something has. It’s closely related to, but not the same thing as, the concept of heat.

Now, if you had a powerful enough microscope and looked at an object that’s heating up, you would see its molecules or atoms vibrate ever more intensely. This motion, ultimately, is thermal energy. Just like a wind chime in motion produces louder sounds the more its parts collide, an object’s particles generate more thermal energy the more they move. This type of particle activity is known as Brownian motion.

What we perceive as ‘heat’ is a transfer of this energy. Concepts of ‘hot’ and ‘cold’ are only applicable in relation to something — for example, a cup of boiling tea is hotter than a cube of ice but much colder than the sun. In order for you to perceive an object as hot or cold there needs to be some way for that energy to transfer between the object and your body. If it has less energy it will draw some away from your body, and your brain tells you it’s cold. If it gives you energy, you perceive it as hot.

A schematic showing the chaotic nature of Brownian movements. Image via Wikimedia.

In general, all bodies exchange heat with those around them (in a physical sense, even the atmosphere, the planet, or the universe are bodies) as long as they are in thermal contact. This ultimately leads to heat being more or less equally distributed in a system — hence why we have the idiom of something being “room temperature”. It’s everything in the room, from the table to the air itself, sharing the same heat energy so they will all feel about the same temperature to us.

Broadly speaking, we measure thermal energy using two units of measurement: the British thermal unit (‘Btu’ or ‘B. Th. U.’), or the French thermal unit (the ‘calorie’). They both largely function the same way, describing how much energy is needed to heat up a certain quantity of water by a certain temperature. However, they differ in how they measure these. One Btu represents the thermal energy needed to raise the temperature of one pound of pure water by one degree F. The calorie uses that most unholy of constructs instead — the metric system, — and describes how much energy you need to heat up one kilogram of pure water by one degree C.

Okay, so quick recap. Temperature is a way to measure the internal energy of a body, and that energy manifests as movements on the molecular and atomic levels. What we feel as hot and cold is a flow of this energy from one body to another. In general, all bodies that come into contact try to equalize their internal heat levels.

Doing a hot take

Given that thermal energy has a corresponding, physical representation in the movement of particles, it stands to reason that if you can make them stop, you can cool down an object. The fundamental problem with this, however, is that heat is the residual form of energy in our universe. Every other type of energy eventually will degrade into thermal energy through physical work, but we can’t run the process in reverse and turn thermal energy into another type of energy directly.

The motions associated with thermal energies are chaotic, and carry extremely low levels of energy individually — making it impossible to ‘harvest’ it to do physical work (due to entropy). This is why mechanisms like steam engines use heat (a ‘flow of thermal energy’) instead.

Now, from what we’ve seen so far, it seems that the way to cool down a glass of water is to cool down a room, and the best way to do that is to cool down the planet. Needless to say, we’re doing the exact opposite today and yet still get our chilled beverages. We have two main ways of doing this: ventilation and refrigeration.

Old mineshafts are great examples of man-built natural ventilation systems created to supply fresh oxygen, not as temperature controls. Image credits Jennifer Ditscheit.

Ventilation is the simpler approach, and we’re not the only ones to do it. In essence, ventilation relies on heat imbalances between two physical bodies to move masses of a medium (usually air or water) around. Because thermal energy is represented by molecular movements, having a current of air go over an object will lower its temperature as these vibrations are transferred to air molecules and carried away. Ventilation is how your computer keeps cool, and it is a part of how air conditioners work, as well.

The main limitation of this process is that it stops working when the object reaches the same temperature as its environment. At that point, the transfer of heat can stop altogether, or change directions from the environment to the body itself, heating it up.

This being said, a flow of air can provide a cooling effect even when the medium becomes quite hot. That’s why the breeze is soothing even on a scorching hot day, and how termite nests keep cool even in the hottest conditions.

Refrigeration is more technically challenging, but it can be used to lower an object’s temperature below that of the ambient environment. The heat removed from this object must be dumped into an area with a higher temperature, meaning energy must be expended in the process (as it creates a physical imbalance). It is this process that allows your air conditioner to hold a certain temperature, your freezer to freeze, and so on. The secret behind this process lies in manipulating another physical parameter: volume.

Squeeze for hot, relax to cool

Image credits hvactrainingshop.

First, you need to know that refrigeration systems need a special medium, known as the refrigerating fluid or agent, to work. This agent will physically carry heat from one part of the system to another. The requirements for a good refrigerant are a low boiling point, a relatively low density in liquid form but a high one as a gas, and that it has a high heat of vaporization (it can absorb a lot of heat before turning into a gas).

The magic happening inside a refrigeration unit hinges on changing the pressure of this fluid along the refrigeration system. At one end of the system, a component known as the compressor squeezes the agent hard, lowering its volume. This step causes it to heat up rapidly (because it holds the same amount of thermal energy but in a smaller place — more collisions happen). Although it’s becoming compressed, the fact that it’s heating up keeps this fluid in a gas state. It’s important that the process does not result in the refrigerant becoming a liquid, since liquids can’t be compressed, and this would damage the system.

As it leaves the compressor, the refrigerant is a hot vapor, at roughly 120° to 140°F (48° to 60°C).

The high-pressured fluid is then allowed to exit the compressor and naturally flows to areas of the system where pressure is lower. The next component it flows into is called the condenser or outdoor coil. Here it is allowed to cool down by passing heat off to the environment. Because the agent coming into the coil is so hot it will still naturally pass off its thermal energy even when it’s hot outside. This is why the back of your fridge is always so hot, or why air conditioning units blow a current of hot air.

The fluid is kept pressurized in this component, but it’s still too hot to turn liquid. As it exits the coil, however, it is fed through an expansion valve. This component allows it to turn into a low-pressure liquid through a process known as flashing. If you’ve ever used a can of compressed air or a fire extinguisher, you’ll know that fluids become significantly colder when the pressure drops / they increase in volume. This is the step that actually cools the fluid down enough to be useful for refrigeration.

Now a liquid, it is fed through the evaporator. This takes the shape of pipes inside the fridge, for example. Being very cold at this point, it absorbs heat, essentially draining thermal energy from the surrounding environment and starts boiling. In an air conditioner, a fan blows air over the pipes or radiator containing this liquid to pump cold air into the room.

The fluid, now back in a gas form at roughly room temperature, is pumped back into the compressor and the cycle repeats.

Reverse perspiration

When we sweat, water on our skin evaporates — it increases in volume — which makes it drain thermal energy from our bodies. This cools us down and makes our environment more humid.

The evaporator works in reverse. Water condenses on these cold surfaces, meaning it cedes its own thermal energy to become a liquid. This heats the refrigerant up and makes the environment very dry. Air conditioning systems are thus also able to dehumidify air in a room or to control humidity levels.

Refrigeration works because all the individual steps — compression, condensation, and evaporation — are forced to happen in different places, which shifts thermal energy around. So whenever you’re using your air conditioner at home, know that it’s not really ‘absorbing’ heat, it’s just taking it from inside and dumping it outside. Thus, fridges, freezers, and air conditioners are a great example of the First Law of Thermodynamics, that energy cannot be created or destroyed.

But it can, with some tricky engineering, be moved somewhere else to make us all more comfortable and safe.

Credit: Pexels.

Solid-state refrigerators based on “plastic crystals” could one-day revolutionize cooling

Credit: Pexels.

Credit: Pexels.

The refrigerator is one of the most useful and valuable modern inventions. It forever changed our way of life, allowing food to be stored for much longer without having to change its taste or texture by pickling, potting, drying or salting it (the traditional way of preserving food before mechanical refrigeration appeared). But despite the fact that they’ve been around for more almost a century, refrigerators haven’t changed that much. They’re still essentially bulky boxes powered by compressors that move environmentally-taxing chemicals — but this seemingly timeless design may soon change.

Researchers at the University of Cambridge are experimenting with a new kind of refrigerating agent called “plastic crystals” which switch from a disordered phase into an ordered phased when pressed by a mechanical force. During the phase switch, the temperature rises and this extra heat is absorbed by the environment. This leads to a drop in pressure that forces the crystals back into an ordered state, causing the temperature to drop.

This pressure and temperature cycle is the same as the one used by a conventional refrigerator. However, your kitchen fridge cools things with a compressor (which is very bulky, constraining the product’s design) that raises the pressure of hydrofluorocarbons (HFCs). The gases — also used to cool cars and buildings — pose a rapidly growing climate threat, trapping heat in the atmosphere. They’re nearly 10,000 times as potent as carbon dioxide and unless their growth is checked, their emissions could double by 2020 and triple by 2030, according to U.S. data.

“If we can do the same job with a solid, it will be better for the environment,” Xavier Moya, a materials scientist at Cambridge University in the U.K., told Inside Science.

In a recent study published in Nature Communications, Moya and colleagues showed that plastic crystals of neopentylglycol (CH3)2C(CH2OH)2 display thermal changes comparable to HFCs.

In the future, solid-state refrigeration could lead to more compact and flexible devices compared to traditional ones. Vapor compression systems generally occupy a lot of space. Without the need for a bulky compressor and extensive pipes for vapor, solid refrigerators could theoretically be small enough to cool microchips.

Before solid-state fridges become a reality, there are some engineering challenges that need to be solved. One is hysteresis, which occurs when the system’s output depends not only on its present inputs but also on past inputs (when the system exhibits memory so to speak). In this particular case, the temperature of the plastic crystals doesn’t return all the way back down to its original temperature, so each cooling cycle becomes less efficient. Another downside is that plastic crystals require a huge pressure to operate, hovering at around 2,500 bars, compared to only 50-100 bars in traditional refrigerators.

According to the Cambridge researchers, it might a decade before plastic crystal refrigerators enter the consumer market. They are currently testing the technology under a spinoff which is already collaborating with manufacturers.

Refrigerator handles.

Plastic crystals identified as a solid, safe alternative to our refrigerants

With refrigeration sucking up about one-fifth of all the energy we produce, the pressure is on to find an alternative. Luckily, a new paper says pressure is exactly what we need. Pressure and plastic crystals.

Refrigerator handles.

Image via Pixabay.

Researchers from the University of Cambridge and the Universitat Politècnica de Catalunya report that plastic neopentylglycol (NPG) crystals can pose a real alternative to the gas coolants of today. When placed under pressure, these crystals show “extremely large thermal changes,” the authors explain.

Cool under pressure

“Refrigerators and air conditioners based on HFCs and HCs [hydrofluorocarbons and hydrocarbons] are also relatively inefficient,” says Dr Xavier Moya from the University of Cambridge, who led the research.

“That’s important because refrigeration and air conditioning currently devour a fifth of the energy produced worldwide, and demand for cooling is only going up.”

HFCs and HCs are currently used in the vast majority of refrigerators and air conditioners. They’re toxic and flammable, and become powerful greenhouse gases when they leak. HCs also deplete the ozone layer. They’re not that good at being coolants, but they are the best we currently have available on a commercial scale.

Moya, alongside Professor Josep Lluís Tamarit from the Universitat Politècnica de Catalunya, is one of the researchers working on finding a replacement. They report that plastic crystals of NPG could fit that role. The material is widely available and inexpensive right now, and is used in paints, polyesters, lubricants and various other chemical products. It also functions at normal room temperatures and conditions.

Conventional cooling technologies use fluids to ‘carry’ heat around. To do so, this fluid is turned into gas then back into a liquid form in successive cycles. It absorbs energy as it expands (like water does when it boils) and releases then it as it compresses. Most cooling devices today work using fluids such as HFCs and HCs because they eat up a lot of energy as they expand.

The solid alternative proposed by the team cools down through changes in its microscopic structure — caused by a magnetic field, an electric field, or through mechanical force. It’s a well-documented reaction, but fluid coolants outperformed them in terms of efficiency, so they aren’t widely used. NPG plastic crystals, however, are on par with these fluids.

Neopentyl glycol.

A neopentyl glycol molecule in 3D. Looks plump.
Image via Wikimedia.

What sets it apart from the rest is the shape of its molecules. They are nearly spherical and only establish weak interactions with each other. This makes it behave a bit like, but not exactly as, a liquid. The term “plastic” in their name refers to them being malleable, not to the material plastic. Because its molecules can be moved around much more freely than that of previous solid coolants, compressing NPG generates “colossal barocaloric [relating to pressure and temperature] effects,” the team writes.

“Here we show that plastic crystals of neopentylglycol display extremely large pressure-driven thermal changes near room temperature due to molecular reconfiguration,” the team writes, “that these changes outperform those observed in any type of caloric material, and that these changes are comparable with those exploited commercially in hydrofluorocarbons.”

“Our discovery of […] should bring barocaloric materials to the forefront of research and development in order to achieve safe environmentally friendly cooling without compromising performance,” they conclude.

Moya is now working with Cambridge Enterprise, the commercialization arm of the University of Cambridge, to bring this technology to market.

The paper “Colossal barocaloric effects near room temperature in plastic crystals of neopentylglycol” has been published in the journal Nature Communications.

The double loop travelling wave thermoacoustic refrigerator (TWTR). Credit: Tokai University.

Novel refrigerator turns waste heat into sound waves to cool down stuff

The double loop travelling wave thermoacoustic refrigerator (TWTR). Credit: Tokai University.

The double loop travelling wave thermoacoustic refrigerator (TWTR). Credit: Tokai University.

Japanese researchers have demonstrated an innovative refrigerator that employs a thermoacoustic engine to cool things down to a minimum temperature of -107.4 C. This sort of heat engines based on sound waves have been researched since the 1990s for generating clean energy but it’s only recently that they’re proving to be efficient. The ‘sound wave refrigerator’, for instance, works on waste heat alone which can be as low as 270 degrees C.

thermoacoustic (TA) engine‘s operating principle is centered around the heating, cooling, and oscillation of gases enclosed in dedicated cavities. Typically, helium is used.

Your everyday Stirling engine works by shifting cool air to a hot heat exchanger. As the air is heated, it expands driving some kind of machinery. This hot air then comes in contact with a cold heat exchanger, contracting and yet again turning the piston, for instance. The TA engine is a variation of the Stirling engine with some key distinctions. For one, the TA doesn’t use moving parts at all. Instead, gas is pushed around by momentum in the form of sound waves.

A normal refrigerator, on the other hand, has loads of moving parts which limit its efficiency. To keep your food optimally cold, a refrigerator first pumps a refrigerant from outside the unit into a compressor. The high pressure generates a lot of heat which is lost to the ambient air and, as a result, the gas condenses into a liquid. The liquid, which still under a lot of pressure, is then passed through a series of valves that moves the agent from high pressure to low pressure. Yet again the refrigerant undergoes a phase change, this time from liquid to gas. The gas expands rapidly — this is very cold gas now, which is pushed up into metal coils inside of the fridge.

Thermoacoustic compressors, however, dispense with many of these mechanical parts. Instead of mechanical compressors,  loud sound waves at resonant frequencies can just as well generate compression of the gas. The process is theoretically more efficient, and refrigerations would no longer require special refrigerants which are damaging to the environment and human health like the chlorofluorocarbons or ammonia.

Though the technology is thought to be very promising, several limitations have kept consumers away. One of the main problems is that previous designs required operating temperatures in excess of 500 degrees Celsius. The designs couldn’t be scaled very well for most applications like heavy industrieseither.

The new engine designed by Shinya Hasegawa and colleagues at Tokai University, however, operates at less than 300 degrees Celsius which is the temperature of more than 80% of industrial waste heat. At this source heat, the TA engine could produce gas oscillations at 85 degrees, lower than the boiling point of water.

“TA engines do not have moving parts, are easy to maintain, potentially high efficiency, and low cost,” says Hasegawa, an associate professor at the Department of Prime Mover Engineering, Tokai University, Hiratsuka, Japan.

The TA’s configuration consists of three etched stainless steel mesh regenerators  fixed in optimal positions. The diameters of the regenerators ranged from 0.2 to 0.3 mm. Heat exchangers made of parallel copper plates were used.  The secret to the new refrigerator’s performances lies in how these regenerators and heat exchangers were positioned. By finding that ‘sweet spot’, the Japanese researchers were able to provide more cooling power with less heat input, as reported in Applied Thermal Engineering and the Journal of Applied Physics.

Now, the team is concentrating on adapting the design so it fits industrial applications. There are many industrial consumers who could significantly increase their energy efficiency, and thus cut on greenhouse gas emissions, by turning some of their waste heat into useful energy. A miniature version could, for instance, fit in your automobile where it can power the air conditioning.

Creative new refrigerator keeps things cool without electricity

Credits: University of Calgary

For most of us, a refrigerator is simply a given – we couldn’t even imagine life without it. But for over 1.3 billion in the world, that’s not the reality, and one of the causes is the lack of access to electricity. With that in mind, a team of students in Canada invented a cheap, portable cooling device that doesn’t need any electricity.

“We thought it would be good to decrease the amount of food waste in the world, and we came up with this design because it’s easy to build and the materials are relatively cheap,” one of the students, Michelle Zhou from the University of Calgary, said in an interview.

The invention won first place in the student category of the 2015 Biomimicry Global Design Challenge, which asks researchers but also students to address critical sustainability issues with nature-inspired solutions. This year seems to have been specifically focused on food.

The way this works is it passively draws warm ambient air through the funnel, which is fed into a pipe that’s been buried underground. This already somewhat cools up the air, which is fed to coiled cooper pipe that’s been immersed in water in the evaporation chamber. The evaporation processed is sped up by a solar-powered fan. The water evaporates around the pipe, chills the air inside and then goes back underground before entering the refrigeration chamber. Of course, this mechanism isn’t anywhere near as efficient or as large as a regular fridge, but it can do very well at keeping produce cool, ensuring that they last way longer. It’s especially suitable for remote areas.

The next step is to ensure a constant temperature of 4.5 degrees Celsius, which is needed to keep most foods from spoiling.

“Anywhere from a quarter to half of the world’s food goes to waste every year, and in rural populations – about 70 percent of the people in rural Africa don’t have access to electricity,” team member Jorge Zapote told CBC News. “So this at the moment uses a tiny bit of electricity from a solar panel, but the end design is to use zero electricity. So this could really help people in those areas.”


How long does food stay fresh? Learn what expiration dates really mean

It happens to everyone – you open up the fridge, pick up that tasty chocolate or pizza you were saving for a late snack and then disaster strikes: it’s past its expiration date. After much woe and gnashing of teeth you throw it in the bin and eat something that makes you feel miserable, like a cucumber.

Oh the horror.
Image via organicfacts

Presumably frustrated from over-snacking on cucumbers, experts did the math and estimate that $165 billion worth of perfectly edible food gets tossed each year, due to it passing its expiration date. But most of these dates are simply inaccurate – or made up.

In this week’s episode of Last Week Tonight, John Oliver hilariously explains why the expiration dates are bogus, and speaks up against food waste and irresponsible managing of food resources. I know, I know, John Oliver is a comedian, not a scientist, but he does make some very valid points and the science agrees with him.

According to the National Resource Defense Council, the “sell by” dates do not indicate whether or not foods are safe to eat – they simply tell you when food will reach its limits for “optimal quality”.

“Sell by”, “best by” and “used by” dates

We see these on every food product, and we have a very limited understanding of what they mean. Unsurprisingly, it’s best to purchase a product before the “sell-by” date, The USDA advises.

“Best if used by/before” dates indicate when the product will have optimal taste and quality. “Use by” dates simply indicate the last day the food will be at its top quality.

the USDA also notes that it’s okay to eat these foods past the dates on the packaging – as long as the package is intact and the item is handled correctly.

“If foods are mishandled,” the USDA writes on its website, “food borne bacteria can grow, and if pathogens are present, cause foodborne illness – before or after the date on the package.”

The only exception is infant formula, as the USDA advises parents to not buy or even use baby formula once the “use by” date rolls around. So, this leaves us with one question:

So how long will it keep?

The answer differs from food to food.


Uncooked Poultry
Image via bridgat

USDA – in a refrigerator for one to two days after purchase.

StillTasty – in the freezer for nine months.

If cooked and the packaging is unopened, it will last roughly three to four days. Once opened, the chicken will last three to four days, as well.


Uncooked beef, veal, pork, and lamb
Image via youronestophalalshop

USDA advises consumers to pay heed to the “use by” date, you don’t need to pay any mind to the “sell by” date.

StillTasty – keep beef in the freezer for six to twelve months, and it will remain top quality.

The product will stay good for three to five days after purchase.


Image via bgr

 Eggs are pretty controversial. If eggs simply have a “sell by” date, feel comfort in the fact that you can store them for three to five weeks after purchase. You can keep them frozen for up to a year.


Image via drinkamara

USDA advises you to adhere to “use by” dates, the “sell by” dates, once again, don’t matter much.

StillTasty – Once you open it, you have seven days to eat the bacon.

If left unopened, you can keep bacon in the fridge (40 degrees Fahrenheit) for two weeks.

Lunch Meat

Lunch Meat
Image via wikipedia

USDA – it will keep for two weeks with an unopened package for a “sell by” date. Once you open the package, you only have three to five days left.

StillTasty – keep commercially packaged lunch meat (ham) in the freezer for one to two months!


Image via glossophilia

StillTasty – commercially packaged nuts will keep for 10 to 12 months in the pantry,

Peanut Butter

Peanut butter
Image via huffingtonpost

StillTasty – you will get three months out of the peanut butter if you leave it in the pantry. However, you can (slightly) maximize the lifetime of your opened peanut butter if you refrigerate it – the shelf life will be three to four months.

Once you open a jar of peanut butter, you can get three to four months out of it.


Image via wikipedia

 StillTasty – you can store chocolate at room temperature to get six to nine months out of them. (Even if they’ve been opened.)

Additionally, StillTasty writes that you can extend chocolate’s life by cranking down the temperature.

“As a general rule, refrigerating chocolate can extend its shelf life by at least 25 percent, while freezing can prolong it by 50 percent or more. Place the original box in a heavy-duty plastic freezer bag, seal it tightly and then refrigerate for up to one year, or freeze for up to 18 months for best quality. Thaw frozen chocolates in the refrigerator,” the website advises.

However, StillTasty mentions that this is not the case for luxury, artisanal, handmade chocolates – at room temp, they’ll stay fresh for two to three weeks.


Image via huffingtonpost

StillTasty – If refrigerated, “milk will generally remain drinkable for about one week after the “sell by” date on the package.” You can extend milk’s life to about three months by freezing it. (The texture might be grainy, StillTasty notes, but thawed milk works for baking.)

A general rule of thumb for milk is this: “sour smell, an off-white or yellowish tinge to the color, and a thick or clumpy texture” means it’s time to toss the milk.


Image via amymyersmd

StillTasty -If you purchase commercially packaged, already refrigerated yogurt, you can keep it for about seven to 10 days after the “sell by” date. If you freeze the yogurt, you can get one to two months out of it. Opened yogurt will taste optimal for five to seven days after it’s opened.

How to tell if it’s gone bad? Just check and use common sense. StillTasty says red flags include “a highly runny watery consistency, a clumpy texture, and a sour smell.” If you see mold, throw out the whole package. (“Do not taste the yogurt first,” StillTasty wisely advises.)


Raw salmon
Image via maryebele

StillTasty – Unopened salmon will last one to two days from the date of purchase. However, if you freeze it (before the one to two days mentioned previously, that is), you can squeeze out an additional two to three months for optimal taste.


Image via cruwineinvestment

StillTasty – While it’s generally frowned upon to serve cold red wine, sticking opened red wine in the fridge will help it maintain freshness (it’ll last an additional three to five days after you pop the cork). Stick opened red wine in the freezer, and it will stay for another four to six months! Opened white wine lasts just as long.

If you’re a light drinker, it’s wise to purchase a full-bodied wine (think merlot or syrah versus pinot noir), StillTasty says. Those variations of wine last longer.

Unopened red and white wine will last three years and beyond, depending on how fine it is. Quality wines can last up to 100 years!


Image via peopleforplants


StillTasty – Left in the pantry, honey will last forever!

Finally, cucumbers

Cucumber. Oh the absolute horror!
Image via 2headsolutions

StillTasty – left whole, a cucumber will last for about a week in the fridge. StillTasty advises against freezing them, and suggests refrigerating in a plastic bag. Sliced or chopped it will last for a maximum of two days in a covered container or wraped tightly in aluminium foil or plastic wrap.