Food Preservation

Introduction

Refrigeration releases green house gases. As our planet gets warmer, people rely more heavily on refrigeration to preserve food and keep ourselves safe from hotter weather.

CFCs

CFCs were banned for damaging the ozone, but harm still persists even as governments progressively ban gasses, in the hunt for progressively less harmful gases. 

Other types of gasses still do damage, so scientists and governments are on a perpetual hunt for less harmful gases and more efficient cooling solutions. 

Electricity Use

Unfortunately refrigeration also uses a lot of energy, on farms, trucks and ships, at warehouses, in stores, and restaurants. A fridge in the average US home uses and estimated 7% of at home energy use.

The Australian government states that "Refrigeration can be responsible for 25% to 85% of total company energy use. Many refrigeration systems are ageing and inefficient, so there is often potential for major energy-saving improvements." Their page on the topic notes that, "Walk-in cool rooms and freezers are mostly operated by small-to-medium enterprises. The average potential energy waste of a unit is over 25%." This link lists a variety of ways businesses can reduce emissions from finding ways to reduce their reliance on refrigeration, to better insultation, improved layout and pumps.

When to Replace

According to the government's recommendations, "If the refrigeration system is more than 10 years old, it should be considered for replacement. An efficient new system could save up to 30% in energy use." 

Power-Free (Passive) Cooling

All of these options can keep food from spoiling without leaking harmful emissions like electric models do, but the coolers work best if built or stored in a shaded location. The MittiCool Earthen Fridge, ZEEC, and Zeer Pot all require water to function, using evaporation.

Energy-Efficient/Refrigerant-Free Cooling

Heat Pumps

During research for this website, heat pump technology came up as a ecologically friendly alternative to A/C and indoor heating.


Currently energy and emission savings are around 75% for these heat pump alternatives (in other words a home owner or tenant would only have to use 25% of the energy to cool or heat a building or room to the same temperatures as a traditional appliance). 


With ground sourced, air sourced, and water sourced heat pumps becoming more widely available, it seems almost strange that heat pump refrigerators aren't also being piloted by companies yet. 


If anyone knows more about this subject, we'd like to be able to provide more about this idea.

Clay Refrigerator

MittiCool 

According to the MittiCool website, "This all-natural clay refrigerator is a flagship product by MittiCool, a venture that is rooted in the concept of going back to our roots to revisit a healthier, more robust lifestyle. Made from terracotta clay, the MittiCool refrigerator is ideal for storing water, milk, fruits and vegetables. This award-winning product provides efficient cooling without electricity.

TerraCooler

The Terracooler is the UK's version of the Mitticooler. It's a modular set of clay containers without the water storage or glass door offered by India's Mitticooler.

Fireless Cookers

Also known as warming baskets have been reported to help produce keep well. 

Root Cellars

"A root cellar (American English), fruit cellar (Mid-Western American English) or earth cellar (British English) is a structure, usually underground[1] or partially underground,[1] used for storage of vegetables, fruits, nuts, or other foods. Its name reflects the traditional focus on root crops stored in an underground cellar, which is still often true; but the scope is wider, as a wide variety of foods can be stored for weeks to months, depending on the crop and conditions,[1] and the structure may not always be underground.[1]" - https://en.wikipedia.org/wiki/Root_cellar 

DIY Guides


Further Reading:

Life Expectancy:

Pro: Saves money since these don't require energy to run. Improves food security since you can store garden and farm produce without fear of power outages.

Con: Learning curve as you work out what you can store and how best to do so. Some crops can cause others to spoil if kept too close together. "You need to keep your root cellar floor moist, deal with mold and mildew, regularly remove rotten or damaged produce, and manage pests." "Depending on the materials you use, building a root cellar is a labor-intensive project that can take several weeks and cost thousands of dollars." - https://www.angi.com/articles/what-root-cellar.htm 

Materials: May include sand bags, barrels, lumber, barbed wire, stone, bricks, nails, etc. You may also want to cover the root cellar with sod and plants such as grass. Water is also needed to keep the floor damp. Shelving or other types of storage inside the cellar can help with organization and keeping certain foods safe from one another, as well as pests or mold.

Yakhchāl

"A yakhchāl (Persian: یخچال "ice pit"; yakh meaning "ice" and chāl meaning "pit") is an ancient type of ice house, which also made ice. They are primarily found in the Dasht-e Lut and Dasht-e-Kavir deserts, whose climates range from cold (BWk) to hot (BWh) desert regions.

...

The structure typically had a domed shape above ground, a subterranean storage space, shade walls, and ice pools.[2] It was often used to store ice, but sometimes was used to store food as well as produce ice. The subterranean space and thick heat-resistant construction material insulated the storage space year-round. These structures were mainly built and used since ancient times in Persia.[1]" - https://en.wikipedia.org/wiki/Yakhch%C4%81l 

The links below offer more diagrams and other info:

Ancient Ice-Making Machines Found In Persian Desert, The Yakhchāl a 2:24 minute video about these ancient cooling devices.

Zero Zero Energy Cooling Chamber (ZECC)

Build Your Own Zero Zero Energy Cooling Chamber (ZECC)

A 12:23 minute using bricks, sand, crates, a woven lid, and leaves. Water required for evaporative function.

Refrigeration-Free Storage: 

Stable-Temperature Storage

You might also consider food preparation options that produces products which don't require cooling such as:

Air Drying 

After air drying, you will probably want to put the food into some glass jars to reduce oxygenation, which causes nutrient loss over time. Silica packs or rice can also help reduce moisture content, further reducing opportunities for mold growth.

Canning (Preserving in Jars)

Fruit Preserves & Jams

This method may require some upfront energy use if you are cooking up some jam or fruit preserves. Jars can be stored for several years, but should be refrigerated after opening, especially if you live in a warmer climate.


Pickling 

This methods traditionally used raw produce with brine, herbs, and/or spices, instead of cooking. This method uses natural, healthy bacteria plus time to ferment foods instead of the faster method which cooks off some nutrients. If you use the traditional, non-heated method you'll need to check and burp your jars daily (sometimes several times a day) which can ensure you find any problems such as mold early enough to save your food.

The traditional method uses more energy to make and may make less nutritious food, but the traditional method might not be as easy or appropriate if you struggle with memory or ADHD. I've sometimes forgotten my jars for a day or more to find the brine has overflowed only the shelves of my cupboards, so I try to pickle when life is less hectic to avoid disaster. Using a calendar and daily alarms can also help you stay on track.

Jars can be stored for several years, but should be refrigerated after opening, especially if you live in a warmer climate.

While pickling and fermenting create similar results, the main take away for the topic of this page, is that pickling requires the cooking of foods, and produces a shelf-stable product. 

Fermentation on the other hand requires zero cooking, but when the food reaches the desired flavor, the product needs to be refrigerated the end the fermenting process.

Salted Foods

Salt pulls moisture out of cells, removing a key element that molds need to be able to survive and grow. That said, this article explains the dangers of relying on salt for your food safety.

Pro: Traditional/ancient art of food preparation.

Con:

Solutions: 

Resources:

Sun Drying

Organizations

North America

USA

New York