When you pick your tomatoes, if you want to keep them longer, you have to find a way of reducing the temperature. As availability of electricity at village level can be a problem, ways have to be found to lower the temperature of this fragile crop. Some farmers at Dambatta in Kano State, Nigeria have used local mud bricks to make a very effective cooling chamber. Watch the video at AccessAgriculture. Via Practical Action.

Joey Hess has designed, built and tested an off-grid, solar powered fridge, with no battery bank. Using an inexpensive chest freezer with a few modifications, the fridge retains cold overnight and through rainy periods. The set-up consists of a standard chest freezer, an added thermal mass, an inverter, and computer control. He writes:

The battery bank is a large part of the cost of a typical off-grid fridge installation. It needs to be sized to run the fridge overnight, as well as for several days of poor weather. Cheaper batteries only last 3-5 years, and longer lasting batteries are correspondingly expensive; either way a battery bank for an off-grid fridge is extremely expensive over the lifetime of the fridge. By storing solar power in the form of cold, I can avoid the battery bank expense and environmental footprint. The only battery power it needs is enough to turn it off cleanly when the solar panels stop producing — a few minutes of power instead of days — and a small amount for its computer control.

Joey’s off-grid, solar powered, zero-battery-use fridge has successfully made it through spring, summer, fall, and winter:

I’ve proven that it works. I’ve not gotten food poisoning, though I did lose half a gallon of milk on one super rainy week. I have piles of data, and a whole wiki documenting how I built it. I’ve developed 3 thousand lines of control software. It purrs along without any assistance.

Read more:

• Fridge 0.1
• Fridge 0.2
• Fridge data
• Fridge Wiki

Related:

• “Daylight Drive” DC Solar Power at the Living Energy Farm

Thanks to Roel Roscam Abbing.

There is a moment in the life of fruits and vegetables that has always puzzled and fascinated me. Put out a dish of strawberries, and in days some darker spots will appear. Maybe a thin tendril of mold sprouts out from the strawberry’s body. At this point, you can still eat it, simply by cutting off the moldy bit. But all of a sudden, the strawberry has clearly died. It’s inedible, sour. It has passed over in to the world of bacteria, mold, and minerals—it is no longer a self-regulating organism. It has stopped being an individual, but has become multitudes.

How does this happen? When is an organism living, and when is it dead? Where does death come from, and why does this change of state happen so quickly? Amazingly, we’ve developed some techniques to play with this boundary between life and death, stretch it, and blur it. I’m not talking about cryogenic freezing, blood transfusion, lab-grown meat, or any other modern technology. I’m talking about fermentation, the process of controlled decay of living organisms.

From coffee to ketchup, bread to sausage, wine to cheese, fermented foods are all around us. These types of fermentation tend to happen in far-off factories. Coffee berries are fermented before they’re roasted. To make ketchup, tomatoes are puréed en masse, left to rot, then heated to kill the bacteria. We usually don’t get the chance to see for ourselves the transformation of life—into other forms of life.

But you can. In this essay, I talk about fermentation: what makes it so magical, why people are so afraid of it. I talk about some strategies people use to make fermentation part of their daily life, and why modern life makes it so hard to do so. And finally, I speak to the ethics of fermentation—what we can learn from it and how it can help us think differently.

Taking time

Consider nukadoko, a fermented rice bran from Japan. Stir together salt, water, and bran—with optional ginger, dried fruit, and spices. Then ‘plant’ some vegetables like radish, beets, or carrots, burying them deep in the ‘soil’. Stir up to three times a day, preferably with your hands: get those skin microorganisms in there. After a week, you’ll have an active fermentation. Pretty soon it’ll be so strong that you can plant any vegetable in it and it’ll be pickled within one hour—these are then called nukazuke.

What happened? The salt inhibited the growth of the ‘bad’ bacteria and fungi. Without it, mold would’ve been sprouting all over the place, and the vegetables would’ve become inedible. Stirring it regularly ensures that the rice bran that was exposed to air gets buried again, so that any mold quickly dies in the anaerobic environment. Yeast starts eating the sugars in the vegetables, and then our friend Lactobacillus turns it into vinegar.

Make nuka, and you get to watch the transition from living organism to a crowd of multitudes. The only catch: to care for your nuka properly, you need to stir it daily, sometimes twice a day. The privilege of tending to life and death takes time.

To care for your nuka properly, you need to stir it daily, sometimes twice a day

Rosemary Liss, an artist who works with fermentation in her practice, learned about nuka at Hex Ferments, a group of food alchemists in Maryland, USA. ‘We had a pot and it was like a pet we had to tend to daily. I loved this ritual—the gestures and movements—it felt like a dance. Each day we lifted the heavy crock off the shelf, removed its colorful fabric covering and then unearthed the pickles before aerating the bran and adding fresh veg to the bed for a short lactic sleep.’

In Japan, the nuka gets passed down from generation to generation; each develops its own special flavors. They become unique microbiomes, only able to survive because of the daily work of grandmothers, mothers, and daughters. We have them to thank for this strange gift.

But that daily magic can quickly disappear when you get too precise. When Liss had the chance to start a residency at the Nordic Food Lab, she decided to work on nuka. She spent months trying to perfect it for a Nordic context. As she noted, ‘When this process was removed from the vibrancy of Hex and into a laboratory with only food grade plastic vessels available for controlled research I felt the magic had been lost.’

There’s something about fermentation that transcends exact science: it wants to be integrated into the rhythm of life. This rhythm is erratic; it’s embedded in culture, tradition, and habits.

Low-tech solutions for modern problems

When I talk to people new to fermentation, they often ask if it’s different from canning. According to Alex Lewin, author of Real Food Fermentation and Kombucha, Kefir, and Beyond, fermenting is the opposite: ‘It’s unlike canning—with canning you kill all of the microbes and seal it hermetically. With fermentation you invite the microbes you want and don’t let in the ones you don’t. Fermentation is diplomacy and canning is a massacre. Canning is a high-tech food technology.’

Canning requires glass and the ability to shape metal in very precise ways. That makes canning uniquely modern. Part of the conceit of modernity is that, to solve our problems, we need more high-tech solutions. But many of our problems are caused by technology in the first place—consider nuclear weapons, air pollution, climate change, and industrial food waste. On the other hand, fermentation is low-tech. You don’t need to be an expert to preserve food, or any fancy technology. Just a bucket, some salt, and trust in the world of bacteria and fungi.

One of the charms of fermentation is that it can help us deal with food waste. Our modern food system is extremely wasteful, with 30-40% of food going into the landfill in the United States, with 21% occurring at a household level. What’s more, it’s incredibly energy-intensive: 33% of global warming-related emissions come from agriculture. If consumers were to learn how to ferment at home, they could preserve their food without having to cook or freeze it—both requiring more energy. That makes it a low-tech solution to a high-tech problem.

Fear of having to care

If fermentation is so easy, why isn’t everyone doing it? To write this article, I reached out to friends and friends-of-friends who regularly ferment, asking them why they do it and why they think many don’t.

Ariadna Rodriguez and Iñaki Alvarez run nyam nyam, an art collective based in Barcelona, Spain. Like many people I interviewed, they’ve been greatly inspired by Sandor Katz, writer of books like Wild Fermentation and The Art of Fermentation. So when I asked them why they think some people have negative reactions to it, they cited him: ‘People do project their fears and anxieties of bacteria on fermentation. The ironic thing is it has always been a strategy for food safety.’

They also think it has to do with something else: people’s fear of messing up. As they put it: ‘They’re scared of having to take care of other microorganisms, they say they will have to travel, they will forget. I think it’s about responsibility, a big word nowadays, because the food industry makes everything for you that just needs to go from fridge to pan.’

We grew up hearing the horror stories about botulism and canning going wrong and don’t realize the fermentation process is much different.

Lina and Adam Esbold, a couple from Sweden, shared similar perspectives. ‘Most people’, they said, ‘are skeptical, they don’t like the taste and are put off by the idea of healthy bacteria… Even more people simply don’t care.’ Rosemary Liss, the artist, also thinks it has something to do with people’s fears of food safety. ‘I think the fear of contamination and making one’s self sick is the biggest barrier. We grew up hearing the horror stories about botulism and canning going wrong and don’t realize the fermentation process is much different.’

For Mark Reynolds, who runs Naughty Nettle Medicinals, ‘Lack of experience or first hand knowledge is a key part of this. There are those who try it once and have something go moldy so they won’t try it again.’ And yet, people can also get pretty excited when they first learn about fermentation—and how little responsibility it actually requires. Lewin describes the moment when he learned about fermentation from Sandor Katz’s book. ‘My head exploded—you can do that with food? You can chop up cabbage and leave it on the counter for a month? How is that possible? Part of what appealed to me is how rebellious that is, to cut something up and not put it in the refrigerator.’

Making death part of life

I’ve often met people who tried to ferment something once, and then they either forgot about it or got scared they did something wrong. There are cupboards full of abandoned kombuchas, fridges littered with old kefir and unfed sourdough.

It’s easy to start fermenting, but it can quickly get dispiriting, and then embarrassing. Rodriguez and Alvarez note that many people might worry that they don’t have the time to ‘collaborate’ with these microorganisms. But, they say, ‘the good thing is that you can always start again, you can always put new tea in the kombucha and everything will be OK. So as we say in Spanish: “no hay mal que por bien no venga”‘ (there is nothing bad that can’t be turned into good).

Lina Esbold and Adam Karlsson say it all takes balance and going with the flow. ‘Some weeks the fermentation gets to take more time and energy, but the opposite is also true, and we just let the cultivations whither.’ And that’s OK, too. Lewin learned to keep his projects out in the open: ‘One thing I do is I leave all of my fermentation projects in plain sight. I see them every time I go in the kitchen. It’s like gardening, you go out and you look at it and poke at it every once in a while.’

There’s also a couple of tricks you can practice to keep your fermentations alive. If white mold appears, simply scrape it off and shake it around a bit. Lewin notes that even if it does go bad, ‘it will be very obvious and very visible: fluffy green spores and you throw it away. If you’ve never had kombucha or kimchi, if you don’t know what it tastes like and you don’t know if it’s bad or not, you either take the leap or you find someone who has tried it before.’

At some point, you might get tired of it all. Simply pause your fermentation by putting it in the fridge, or better yet, in the freezer. Fermentation starters can also survive several years when you dry them. Once you’re ready to start them up again, just add whatever it needs (sugar and tea for kombucha, milk for kefir, or flour for sourdough). And yet, even if you try your best, fermentation isn’t always easy to keep doing. Our jobs and school uproot us; we work 9-5 and come home exhausted. For those who work irregular hours, it’s hard to build up the routine and habits needed to maintain that sourdough or make yoghurt or kefir daily.

And then there’s the food system. The supermarket is anathema to fermentation: live fermentation generates carbon dioxide and methane, stinking up the aisles and bursting through the packaging. In other words, it’s messy and weird. Partly because our access to food is limited to what the supermarket has to offer, it’s not easy to get hold of kefir grains or a kombucha mother. And when we do, it’s hard to get guidance. It can be intimidating if you don’t know anyone with experience fermenting.

Our society is also marked by what food researchers call ‘de-skilling’. We’ve largely lost the food practices handed down to us over generations. What remains is a semblance of our past food cultures: fermented pickles become canned; sauces rich in character and variety become, simply, ketchup.

The supermarket is anathema to fermentation: live fermentation generates carbon dioxide and methane, stinking up the aisles and bursting through the packaging.

Part of this is the industrialized food system, but another part is also the way the economy shapes our lives. A few generations ago, most Westerners lived in multi-generational households, children together with grandparents, several families sharing tenements, and a vibrant street culture that came from dense living arrangements and reliance on walking as the primary means of transportation. With modernity, every tradition, every routine, every relationship is constantly shifting and torn apart.

And even though science has given us unprecedented ways to understand the food that we eat, it also has its limitations. It seems like every week a study comes out that overturns the guidelines on what we’re supposed to eat. We’ve grown up with the idea of an official expiration date—leaving our trust in food safety to some largely invisible process, determined by experts. We have the science to understand the invisible stuff going on in our kitchens and in our guts, but a cultural attitude of fear that stops us from playing with our food—an attitude that inhibits microbiomes from flourishing in our kitchens.

When I talked to Jyotsana Singh, a friend, about this, she pointed out that we lack a common sense of how food spoils and what’s safe or unsafe to eat. As she put it, ‘people don’t trust their senses’. Ironic, with so much information available ‘at our fingertips’. She grew up in a family where, when concerned if the milk was OK, they wouldn’t look at the expiry date but instead sniff it. Perhaps due to this common sense she grew up with, combined with a knowledge of basic chemistry and biology, she rarely has a feeling of risk or fear when making food.

Through our conversation, we decided that there’s an important distinction between habits—the kind that allow us to ferment on a daily basis; common sense—an intuition of what’s going on under the surface, informed by today’s science and cultural knowledge; and tradition, where our upbringing guides us with confidence in the food we eat and make. Maybe it’s a balance of these that helps foster fermentation practices.

If you think about it this way, there’s something very political about fermentation. Our job makes it difficult to form daily habits. The modern food system has atrophied our cultural knowledge and traditions of food preservation practices. It makes sense that so many people find it hard to integrate into everyday life. To create a world where fermentation is the norm, we’d need to change the world.

Thinking with fermentation

The living body is always on the point of passing over into the chemical process: oxygen, hydrogen, salt, are always about to appear, but are always again sublated; and only at death or in disease is the chemical process able to prevail. The living creature is always exposed to danger, always bears within itself an other…
-G. W. Hegel, Philosophy of nature

Thus politics… originated in the daily ferment of ordinary life in the agora.
-Murray Bookchin, Urbanization without cities: The rise and decline of citizenship

As Hegel realized two centuries ago, we carry others within ourselves. What makes the body keep its integrity, surrounded by constant danger? The practice of fermentation raises these kinds of questions, and helps us think through a different ethics of being.

For Rodriguez and Alvarez, getting into fermentation opened them up to seeing multiple connections in life. ‘It all feels as part of the same thing,’ they say when I ask them how fermentation is part of their daily life: ‘Eating it. Having something fermented every meal. Then taking care of all the microorganisms that coexist with us, maybe taking out the tea from the kombucha, or changing the water and adding the sugar to the water kefir, tasting how the chilis are doing fermenting in the sun, opening the miso every now and then, and so on and on.’

All of this, they say, helps them visualize ‘all this activity in different scales interconnected between all the agents, our bodies, the microorganisms.’ Fermentation also informed Lewin’s approach to life. ‘Fermenting establishes a dynamic equilibrium of microbes—getting people comfortable with that is hard. In our overly determined world where everyone wants to understand everything completely, a lot of people are uncomfortable making a leap of faith. It’s a good practice to help people let go a bit. Maybe we don’t have to measure everything exactly, maybe we don’t have to control everything completely.’

Maybe we don’t have to measure everything exactly, maybe we don’t have to control everything completely.

To practice fermentation, we need to multiply experiences, not just with bacteria and fungi, but also with each other. It takes human relationships to learn how to ferment, and it takes knowledge given to us through science and culture. It also takes common sense. This common sense emerges through interaction with others. In ancient Athens, strangers met at the agora, the market place. It was here that politics happened, where people could learn to discuss with each other. The agora was messy, it was ordinary, but it was also the foundation of Athens’ democratic system. What kinds of fermented goods, I wonder, were sold in the Athenian agora, and what kinds of political conversations did they provoke?

When modernity meets its end-point and creates a world where everything is sterile, controlled, and known, there will be little space for fermentation. But there will also be little space for free thought: thinking that bubbles up out of the corners, appreciates complexity, multiplies relationships, navigates the subtle contours of life and death.
Modern life makes fermentation unintuitive and difficult. But it’s precisely this practice that can help us come to a different way of thinking and approaching the world. A world where fermentation is integrated into our daily life might be a bit messier, but it would also be more caring to the many life forms with whom we co-exist. Perhaps it would be a world that lends itself to contemplation, letting us ponder the transition of life to death, rather than fearing it, hiding it away.

This article was written by Aaron Vansintjan as part of a collaboration between Low-tech Magazine and nyam nyam, an art collective based in Barcelona (Spain). The article forms part of the project “It is the microorganisms that will have the last word“, selected as an off-site project for Barcelona Producció 2017. The pictures were made by nyam nyam.

Aaron Vansintjan wrote several articles for No Tech Magazine & Low-tech Magazine. He keeps his own blog at Uneaven Earth.

The Kőbánya district of Budapest is situated on the eastern margins of the Hungarian capital city. Beneath Kőbánya there is an extensive limestone layer, in which tunnels and passages have been made, some of which appear to date from the 13th century. In the 19th century, the limestone caverns of the Hungarian capital city Budapest were used for the refrigeration of perishable goods in large quantities.

This article analyses the architectural development of these evidently low-tech facilities, while also exploring their significant role in the city’s urbanisation. The technical functions and structure of the system of caverns may be useful as a resource for society in the future when the supply of fossil fuels runs out.

The effectiveness of the caverns as place for refrigeration can be demonstrated through climatic calculations. The cavern system has significant energy capabilities, given that there is a constant air temperature throughout the year.

Read more: Pilsitz, Martin, and Zsuzsanna Nádasi-Antal. “Historical storage cellars in Budapest: The architectural history and functional operation of an industrial building in 19th-century Hungary.” Építés-Építészettudomány (2018): 1-20.

Archaeologists are trying to definitively establish if mysterious shafts discovered at Switzerland’s extensive Augusta Raurica site in 2013 could have been ancient “refrigerators”. It is likely that the Romans used shafts like the four-metre deep examples at Augusta Raurica – some 20 kilometres from Basel – as cool stores during summer.

The shafts were filled with snow and ice during winter to keep the space cool well into the summer months. This then allowed for everything from cheese to wine and even oysters to be preserved during warm weather.

A first attempt to recreate the ancient cool box failed after archaeologists at the dig filled the shaft with snow all in one go. That experiment showed temperatures in the shaft were above freezing point even in winter. The second try was more successful: the shaft was gradually filled with snow and ice blocks were placed inside as well. Using these methods, snow remained until June.

For their third attempt, researchers used methods developed by the so-called ‘nevaters’ or ice-makers on the Spanish island of Majorca. This will see the researchers placing 20–30-centimetre-thick layers of snow into the shaft. These individual layers will then be compacted down with a straw cover placed on top of each one.

Quoted from The Local: Swiss researchers try to get ancient fridge working (again).

Before refrigeration came into our houses and global supply chains, most of our winter stores were salted, pickled, and dried. Many of the strong compelling flavors found in European delicatessens come via fermentation: cheese, salami, gherkins, vinegar, olives. Likewise the mainstays of Oriental cuisine—soy, miso, and tempeh—and the whole of the world’s drinks cabinet, including everyday luxuries such as coffee and chocolate.

If you were wary of venturing into this unknown territory alone, you could not hope for a more enthralling guide than Sandor Ellix Katz: “My advice is to reject the cult of expertise. Do not be afraid. You can do it yourself.” There is no recorded case, he assures us, of poisoning from fermented vegetables.”

Read more: Fermenting Change. Thanks to Aaron Vansintjan. More low-tech food preservation.

“Bog butter is butter that has been buried in a peat bog. Over 430 instances of bog butter have been recorded. Of these, 274 have been found in Scotland and Ireland since 1817. The earliest discoveries are thought to come from the Middle Iron Age (400-350 BC), though this does not exclude the possibility of much more ancient roots. More recently one firsthand account tells of butter being buried for preservation in Co. Donegal 1850-60. In 1892, Rev. James O’Laverty, an advocate of the argument that the butter was buried for gastronomic reasons, dug some butter into a ‘bog bank’ and left it for eight months. His experiment was carried out in much the same spirit as ours – for analytical purposes and not for a cultural or preserving motive.”

“Peat bogs are, by their nature, cold, wet places; almost no oxygen circulates in the millennia-old build-up of plant material, which creates highly acidic conditions (our site had a pH of 3.5). Sphagnum moss bogs have remarkable preservation properties, the mechanisms of which are poorly understood. Early food preservation methods have been researched extensively by Daniel C. Fisher, in relation to the preservation of meat. In an attempt to recreate techniques used by paleoamericans in North America, Fisher sunk various meats into a frozen pond and a peat bog.

“A key finding from his research is that after one year, bacterial counts on the submerged meats were comparable to control samples which had been left in a freezer for the same amount of time. In fact, suitable foods can probably be aged in many types of soil: salt-rich that will provide dehydration, very cold/freezing that will freeze foods or slow degradation, or, as in our case, anaerobic and acidic conditions to prevent microbial action and oxidation. To our canny ancestors, this preserving characteristic provided an ideal place to bury foods.”

Read more: Bog Butter: a gastronomic perspective. Via The Year of Mud. More low-tech food preservation.

Update: Root Simple links to an interesting video about this primitive food storage technique. Thanks to Ruben Anderson.

It works on the principle of evaporation.  Water from the upper chambers drips down the side, and gets evaporated taking away heat from the inside , leaving the chambers cool.

The top upper chamber is used to store water. A small lid made from clay is provided on top. A small faucet tap is also provided at the front lower end of chamber to tap out the water for drinking use.

In the lower chamber, two shelves are provided to store the food material. The first shelf can be used for storing vegetables, fruits etc. and the second shelf can be used for storing milk etc.  Cool and affordable, this clay refrigerator is a very good option to keep food, vegetables and even milk naturally fresh for days.”

MittiCool Refrigerator. Thanks for the tip, Joseph. See also:

• How to keep beverages cool outside the refrigerator
• Storing fruits and vegetables outside the refrigerator
• Bog butter: storing food in soil

However, people obtained the same result much more sustainably before the advent of the Industrial Revolution. In hot, dry climates, we used porous earthenware jugs that were not only re-usable, but also kept water cool by taking advantage of natural energy sources.

The best known example is the Spanish ‘botijo’, an unglazed ceramic container that cools beverages by evaporation. Similar drinking containers can be found in other Mediterranean countries, as well as in Mexico (where it is known as a ‘búcaro’) and on the Indian subcontinent (where it is called a ‘ghara’, ‘matka’ or ‘suhari’).

The ceramic water cooler probably originated in the Indus Valley Civilization, which would make it 5000 years old.

Illustration: a Spanish botijo.

The botijo generally has a wide, spherical belly with two openings on top — a wide opening to pour water in the jug and a smaller drinking spout — as well as one or two handles to carry it. Traditionally, people drink the water directly from the botijo by holding it up and tilting it so that the water pours from the drinking spout.

Botijo-etiquette demands that the lips do not touch the drinking spout, as the water container is usually shared among several people, and of course the content can also be poured into a glass. The large opening is covered with a cork or a cloth after filling the jug, in order to keep insects out.

Botijos come in different sizes, but on average it contains about 3 litres of water, with larger ones holding up to 7 litres – enough to supply a small group of people with drinking water for a full day.

How does it work?

After the botijo is filled with water, it is preferably placed outside in the shade, although it also works when placed in the sun or indoors. The technology is based on evaporative cooling — the same process that keeps the human body cool by sweating. Because the ceramic jug is not completely water-tight, a small amount of the stored water filters through the pores of the clay and evaporates once it comes in contact with the outside, dry environment. Evaporation (the transition from liquid to gas) requires thermal energy, which is partly extracted from the water inside the jug, cooling it down.

The cooling potential of the botijo

The cooling potential of the botijo depends on — among other things — the shape, dimensions and material of the jug, the quantity of water that it holds, and the humidity and temperature of the outside air. It can be calculated precisely according to a complex mathematical model that was developed during a 1995 scientific experiment (PDF), which showed that under optimal conditions a cooling of up to 15 degrees Celsius can be obtained.

A botijo holding 3.2 litres of water was placed in an oven with a temperature of 39 degrees and a relative humidity of 42 percent, mimicking a hot Mediterranean summer day. It was observed that the temperature dropped by 2 degrees after 15 minutes, by 8 degrees after one hour, and by 13 degrees after three hours. In about 7 hours time, the temperature had fallen to 24 degrees, with a water loss of about 0,4 litres (eight percent of the water content). After that, the temperature slowly started to rise again. At lower outside temperatures (around 30 degrees Celsius), the cooling effect is limited to about 10 degrees Celsius. The cooling effect thus adapts to climate conditions.

Beware of tourist souvenirs

Importantly, a botijo should be unglazed in order to function properly. Glazed botijos – now often sold as tourist souvernirs – do not cool water. Glazed water containers were used to store water in cooler and more humid climates, where a porous container would be of no use.

Similar technologies

A somewhat similar cooling effect can be achieved using a canteen with a lined cover. If the canteen is submerged in water so that the cover absorbs liquid, and is then left outdoors until the cover dries up, the water inside it will have cooled. One can also observe the effect by placing a water bottle inside a thick, wet sock. Evaporative cooling is also the process behind the Zeer Pots – refrigerators that work without electricity – and it can be applied to the cooling of buildings and industrial processes. In fact, the botijo also helps to cool the environment in which it is located, because evaporation takes only part of the required energy from water — the rest is taken from the environment.

Mobile refrigeration device

Apart from the fact that the botijo does not use electricity, it offers a couple of further advantages. Firstly, it produces water that is cool but not nearly as cold as refrigerated water. Ironically, water that is cooled in a refrigerator is too cold for human consumption and can cause health problems.

Secondly, the botijo is a mobile refrigeration device — for which there exists no modern counterpart. Plastic, glass or metal bottles, which have no pores and are thus unable to ‘sweat’, start warming up once they are taken out of the refrigerator.

In contrast, the water in a botijo remains cool regarding of where it is taken, which explains why the device was traditionally used in Mediterranean countries both domestically and by farmers. Travellers often made use of the containers as smaller, cylinder-shaped botijos could be tied to horses. Even a modern, metal canteen with a lined cover does not offer the same benefits as a mobile refrigeration device, because it is not the water inside that cools the bottle. The canteen has to be soaked in water regularly in order to maintain the cooling effect, which is not always an option in a dry climate.

The importance of climate

With the advent of cheap fossil fuels, we have become accustomed to the idea that any technology works anywhere. This is seldom the case with pre-industrial technologies, which are most often local solutions. The botijo is no exception to this rule. It is especially suited for climates with hot, dry summers (type Cs of the Köppen climate classification). This climate prevails around the Mediterranean, and can also be found on the West coast in the United States (in California and Oregon), in South Australia, and in small regions of South-America (in Chile) and Africa (in South-Africa). The botijo also performs excellently in desert climates (type BW, which is much more widespread than the Mediterranean climate).

    With the advent of cheap fossil fuels, we have become accustomed to the idea that any technology works anywhere. This is seldom the case with pre-industrial technologies, which are most often local solutions.

However, the cooling function of the ceramic water cooler deteriorates as summers become more humid, as is the case in most tropical climates. Similarly, the human body is more sweaty in a hot and humid environment, because transpiration cannot evaporate.

Climates with cool and wet summers have less need for water cooling methods in the first place. This explains why some parts of Spain (notably in the north-western region) do not have a tradition of evaporative water coolers, but use glazed containers instead. This is also true for the areas near the coast of the Mediterranean, where the proximity of the sea raises air humidity.

Lifting the botijo

One of the disadvantages of a botijo is that it can be rather heavy for people who lack muscular strength. An average botijo filled with water can easily weigh 4.5 kg. However, there are some solutions to this problem.

Fundación Terra, a Spanish environmental organisation, launched a campaign a few years ago to promote the use of the botijo in homes and offices, and developed a system to suspend the bojito from the ceiling for easy drinking. In addition, they advise people to hang it above a plant so that spilled water does not get lost. In India, the drinking spout was replaced by a low-placed tap.

Kris De Decker (edited by Deva Lee). Sources: 1 / 2 / 3 / 4 / 5 / 6 / 7 / 8 / 9 / 10.

PS: If you are looking for a smaller container, check out these unglazed clay water bottles, presented at the Green Living Show in Toronto two week ago.

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Related articles:

• Storing food outside the refrigerator: Jihyun Ryou’s anti-fridge design
• Bog butter: storing food in soil
• Pottery refrigerators
• California Coolers
• India’s ancient stepwell architecture cools modern building
• Home made air conditioner
• Insulation: first the body, then the home

More low-tech refrigeration.

The cooler cabinets were designed to hold fruits, vegetables, and other staples that needed to be kept cool but didn’t need to take up critical space in the era’s tiny ice boxes. The coolers were open to the basement to draw in cool air, which then wafted up and out a chimney or a wall vent.

When the refrigerator came along, it seems that, over time, the vents were boarded up and the California Cooler was all but forgotten. Today, if you walk the streets of my hometown, Berkeley, where most of the houses were built in the 1920’s, you will see many homes, and even apartment buildings, with the exterior vestiges of these vents.”

Read more: Resurrecting the California Cooler. Thank you, Adriana. Previously: Saving food from the fridge.

Korean artist Jihyun Ryou, a graduate of the Dutch Design Academy Eindhoven, translates traditional knowledge on food storage into contemporary design. She found the inspiration for her wall-mounted storage units while listening to the advice of her grandmother, a former apple grower, and other elderly. Her mission: storing food outside the refrigerator.

On her blog, “Shaping traditional oral knowledge“, Jihyun Ryou explains the motivations underlying her work, which actually go beyond food storage:

“This project is about traditional oral knowledge which has been accumulated from experience and transmitted by mouth to mouth. Particularly focusing on the food preservation, it looks at a feasible way of bringing that knowledge into everyday life. Through the research into the current situation of food preservation, I’ve learned that we hand over the responsibility of taking care of food to the technology, the refrigerator. We don’t observe the food any more and we don’t understand how to treat it. Therefore my design looks at re-introducing and re-evaluating traditional oral knowledge of food, which is closer to nature. Furthermore, it aims to bring back the connection between different levels of living beings, we as human beings and food ingredients as other living beings. Through the objects of everyday life, design can introduce traditional oral knowledge into people’s lives through their experience of using it. Objects make invisible knowledge evident.”

Talking about fruits and vegetables as living beings sounds rather woolly, but it is actually true. Vegetables and fruits continue to live even after they are picked. They keep breathing, taking oxygen from the air and giving off carbon dioxide, water vapour and heat. By regulating temperature and humidity, it is possible to slow down this respiration, resulting in a longer storage time.

Storing food outside the refrigerator

While many fruits and vegetables benefit from the low storage temperature in a refrigerator (around 40 degrees F or 4.5 degrees C), this is not true for all of them. So-called fruit vegetables such as peppers, courgettes, aubergines and tomatoes require higher temperatures and decay more rapidly in the refrigerator. They need high relative humidity, though. The shelf pictured above gives these vegetables a suitable space. Through the ritual of watering them everyday, they will stay fresh. The water not only raises humidity but also cools the produce, assuring a temperature that is higher than that in the refrigerator but lower than that in the room.

The same principle is applied to the fruit bowl shown above, in which a perforated dish sits over a bowl of water. The concept is inspired by the old farmer’s wisdom to preserve fruits fresh before selling.

Damp sand

Keeping vegetables in slightly damp sand has been a storage method for many centuries. While low temperatures are favourable for vegetables like carrots, high humidity is equally important. Keeping them in wet sand can be a good compromise. In the design above, this concept is improved by burying the vegetables upright, mimicking their growth conditions – and making them last longer, says Jihyun Ryou. Just don’t forget to water them from time to time.

Rice absorbs humidity

Other foods, like spices, garlic, onions and sweet potatoes, require low humidity but higher temperatures, which also makes them unstuibale for storage in a refrigerator. Because it absorbs moisture easily, rice can be of great help here. In the design above, the cork lid of each spice container contains a small space holding rice, which helps to keep the spices dry without forming into lumps.

Ethylene gas

Some fruits and vegetables (notably apples but also tomatoes, avocados, bananas, muskmelons, pears, plums, and peaches) emit ethylene gas. This has the effect of speeding up the ripening process of fruits and vegetables kept together with them, which is why it is wise to store ethylene producing fruits and vegetables separately. However, when combined with potatoes, Jihyun Ryou says, they have a positive effect, because the ethylene gas prevents the potatoes from sprouting. The design pictured above consists of a wooden box that keeps potatoes in the dark (a more common way to keep them from sprouting), while the holes on top allow them to benefit from the ethylene gas emitted by the apples.

The same design could also be used to accelerate the ripening of tomatoes, a process that is used – on a much larger scale – by food distributors.

Does it work?

The more food you can keep out of the fridge, the smaller it needs to be and the less energy it will consume. The designs described above show a refreshing way to do that, although it should be remembered that these are artworks, not consumer products. Using similar methods when storing food in a basement or a specially designed root cellar – the traditional way – will give better results (more on that in a forthcoming article). Furthermore, some of the storage strategies followed by Ryou are not generally accepted. Most of the sources that I have consulted (books, not grandmothers) say that ethylene gas will promote the sprouting of potatoes, not prevent it.

Anyway, her work will certainly encourage others to search for alternative storage solutions based on traditional knowledge – and that’s what it is all about. Experience and experimentation will tell what works and what not.

More at Jihyun Ryou’s blog: “Shaping traditional oral knowledge” and in this video. She also offers a beautiful booklet. An overview of temperature and humidity requirements for most vegetables and fruits can be found here (.pdf).

We will publish more on low-tech food storage soon. Stay informed via email, feed, twitter or facebook.

Thanks for the tip, mom!

Related articles:

• The poor man’s refrigerator
• How to keep beverages cool outside the refrigerator
• Pottery refrigerators
• California coolers
• Bog butter: storing food in soil