Why does food have to be so heavy and perishable?
Two questions that people have asked for ages are becoming even more relevant in the modern era of increasingly popular light weight outdoor activities.
They have also been important queries for centuries among those looking to extend the shelf life of their snacks and for hobbyists looking to add spice and garnish to their cooking cabinets.
This historical relationship between food and its heft has been studied by humans to a level of art, then science and, more recently, art again. The reason why food is so heavy and perishable is mostly due to its moisture content. Water is the element that makes food both delicious and easy to chew while also making it such a burden to carry and store. Remove the water, and food immediately becomes more shelf and pack practical.
How to dehydrate food
The three most common methods for removing water from what we eat are:
Traditional, natural methods of dehydrating
Modern, machine driven dehydrating
When deciding what method works best to make waterless food, the answer is a personal preference.
While freeze drying is a good option that certainly holds (and lowers) weight, there are several reasons why someone might choose to forgo this modern method for something old-school, effective and delicious-
Here we take a look at five reasons why dehydrating is both delectable, dependable and preferable.
Cost is the most important reason for someone to choose traditional methods of dehydrating over freeze drying and remains freeze drying’s single biggest barrier to entry. Dehydrating can be performed for little to no cost where an entry level freeze drying unit is thousands of dollars.
Dehydrating is a simple process that uses heat to desaturate food to as low as 10 percent of its original moisture content. Modern technology allows us to do this quickly under controlled conditions for a price, but the original pioneers of dry delectables would simply lay their herbs, fruits and meats outside until they dried out in the heat from the sun.
Heat from the sun is free.
As for machine drying, a basic, entry-level at home dehydrator costs as low as $50, with more advanced amateur appliances costing closer to $300. This expense when compared to that of free sunshine seems like a lot, however when compared to the cheapest quality freeze dryer (usually around $2000), light food begins to feel lighter on the wallet when it's being made in a dehydrator.
How much does a dehydrator cost to run?
Energy costs for a dehydrator can vary, but basic home models that peak at around 700 watts cost on average $0.07 per hour of operation based on the current national average price of electricity at $0.10 per kwh. Small home dehydrators at their peak consume much less energy than the average small home freeze dryer which uses around 1210 watts of electricity, amounting to $0.12 per hour of use.
Over the course of 1000 hours, a dehydrator and freeze dryer would cost $70 and $120 respectively.
Freeze dryers use more energy because they have to freeze food first and although the difference over that many hours may seem benign, for the dedicated or professional snack saver these costs can add up fast. For those conscious of energy usage in the home, like those with solar panels or passive energy systems, the more power conservative dehydrator may be a better choice for their kitchen.
2. Taste and Texture
Commonly, it is stated that freeze drying best preserves the original flavor and texture of food. Dehydrating, however, adds a desirable consistency both before and after rehydrating that gives food a pleasant taste.
Mangoes, for instance, are a commonly dehydrated treat that are best when dried to a certain humidity, that is to say, when not completely dry. Using a common dehydrator makes it easy to fine tune the moisture content of food to specifically suit your taste. Food can remain partially chewy, which is why beef jerky is best made using a dehydrator.
Jerky, fatty foods or any foods with high oil content also falter in a freeze dryer. Sublimation, the process freeze dryers use to dehydrate, works only if the moisture can be frozen first then quickly reheated to a gaseous state. Oils and fats fail to freeze and sublimate like water, so drying meat is tricky if not impossible in a freeze dry system.
Where freeze drying claims to return dehydrated food closest to its original flavor, the fact is that once dried by any method, no food will return to its true original flavor and condition. Both methods give food a particular taste, neither being “worse” than the other, only different, especially depending on the food.
To some, many vegetables taste superior when rehydrated after using a dehydrator. Many vegetables, like eggplant, also dehydrate to a smaller and more compact size when dehydrated versus freeze dried. If a fruit or vegetable has a high water content in its original condition, then it can be made much smaller by drying slowly with heat versus sublimating which sometimes leaves loft in food.
Home dehydrators come in all shapes and sizes. Often available at a local appliance store, dehydrators are simple devices that are essentially small convection ovens.
Freeze dryers, however, generally consume much more space and are less readily available locally.
How heavy are dehydrators?
Of the ten dehydrators sampled, the average weight comes out to 27lbs with weight and size typically increasing relative to the amount of peak wattage (power) the unit generates. The smallest sampled dehydrator (84sq in) is for very casual use on a kitchen counter where the largest (1060sq in) is closer to industrial application and would only fit in a designated space.
The smallest available home freeze dryer from the leading reputable brand is 305 square inches and weighs 61lbs. At that size the freeze dry unit is heavier than all but one of the sampled dehydrators and is in the top three largest footprints. This again, is the smallest of freeze dryers and in any situation would require more than mere counter top space to operate.
It is also worth pointing out that for simple greens like herbs and spices, a common method of dehydrating is simple hang drying. This method requires little to no space, and is often the hallmark of décor for those who love to be surrounded by their plants and greenery (you know who you are).
For other casual hobbyists or those with limited kitchen space it makes sense that a smaller and lighter unit would be preferable. For this person a dehydrator fits the bill, for even one of the larger machines is more compact than the smallest of freeze dryers.
Despite the previous examination of machines and electricity, the truth is that dehydration is an ancient practice so deeply rooted in human history that it predates both.
How did people save food before refrigerators?
Pre-electricity humans had to be creative in finding ways to save food for off seasons. Before refrigerators, people often dehydrated food by wrapping it in leaves and burying it in the sand to save for later. Food was often hung over a fire and “smoked” in the dry circulating air. Dehydrating and smoking are food storage techniques that we still use today.
The first evidence of communities dehydrating their food dates back to as early as 12,000 B.C. and it quickly grew to become a cornerstone of human survival. As cultures grew and became more sophisticated they also started to experiment with spice and garnishes with the intention to not only store food but also bring zest to fresh meals.
Along with other techniques like curing and fermentation, dehydrating became a foundational technique that has allowed humans to grow and evolve into modern society.
The process of free drying is a relatively new invention that became popular during World War II. Originally invented in 1906, it was a useful tool for blood preservation during the war and is now used mainly for food storage. Dehydrating, however, is perhaps more of an ancient art than a science and may be more popular among those who live by the phrase, “if it ain’t broke don’t fix it.”
Where traditional dehydrating never needed fixing, there were some who felt it could be done faster.
The first dehydrator machine was invented in the mid 19th century by the French horticulturalists Masson and Chollet, whose patented process involved thinly slicing fruits and vegetables and hydraulically pressing them into thin wafers before subjecting them to warm air. Although the rehydration procedure involved a sluggish six to eight hours of soaking, it became an important resource for the French Navy looking to transport food by ship over long distances.
The technology has since advanced to become a valuable tool for fun and food loving hobbyists and is still the cheapest and simplest way to lighten and lengthen the life of food.
The long lasting tradition of dehydrating holds value in not only its cultural sense of tradition but also in its essential contribution to the evolution of modern human life. Dehydrating is a method of preparation that connects contemporary life with a historic one, and in practice propagates a fading but important habit- appreciation of one’s food.
We may have our own growing collection of dehydrated food recipes, but compared to that of the dried goodies community at large, we barely scratch the surface of what's out there.
Cooking has been and will forever be a craft of company and companionship, so it is no surprise that those who like to indulge in new forms of creative cuisine also like to share their methods of munch manifestation with others who also do the same.
This essence of social passion for food easily extends into the world of dehydration, as massive communities sharing their process and ideas can be found on line and on bookshelves. Reddit’s dehydrated sub alone has over 88k subscribers, not to mention all of the dehydrated related posts on their regular cooking page.
Books are also plentiful. Amazon offers hundreds of books related to dehydrated food. Jerky, fruits, spices, vegetables, baked goodies, full meals, trail meals- all have been researched and perfected from years of community interest and are expansive for both beginner and savvy dehydrator specialists alike.
Julie's personal creations are well presented in her very own cook book. Along with recipes, she offers dehydrating methods and advice valuable to any at home chef looking to dehydrate some delectables.
If books aren’t enough, blog posts continue to pepper the pantheons of the web. Many of these posts are not only charming and valuable, but are often totally free and offered to help those who are interested get a better sense of important details like time, heat, moisture content, preparation and storage.
The age-old practice of dehydrating provides a connection from one chef to another by focusing on a specific and increasingly popular niche that is both fun and useful for those who desire more desirable lightweight food. Online forums are chock-full of progression photos where those who are less experienced are guided by a community of virtuosos until they get the perfect jerky or pinto bean powder.
To many people dehydrating isn’t just a way to carry backpack food, it’s a dynamic hobby full of different variables worth fine tuning and perfecting to achieve the grandiose satisfaction of a job well done. A blend of art and science, dehydrating has evolved from being a necessity of human life to a rewarding niche of hobby and travel utility, and for that it is important to understand that just because something like freeze drying is newer doesn’t automatically make it better. The choice is a matter of preference and taste, and for many trail cooks out there, it goes to show that there are quite a few reasons to embrace the love of dehydrating; even if the only one they really need is that they simply prefer the taste.