Dehydrated Foods – The history of food dehydration, Why You Should and how To Do It.

In a world where food security and sustainability are becoming increasingly important, dehydrating food has re-emerged as a practical and efficient method for preserving food. This ancient technique, which dates back thousands of years, involves removing moisture from food to inhibit the growth of bacteria, yeast, and mould, all of which need water to thrive. By dehydrating food, you can significantly extend its shelf life, reduce waste, and create a versatile food store that can sustain you and your family through various situations.
The History
Early Britons, living in a climate where fresh food was not always available year-round, quickly realized the value of preserving food through drying. The earliest methods involved using natural elements like the sun and wind to dry foods.
During the Iron Age, drying techniques were used primarily for preserving grains, fruits, and herbs. Grains like barley and oats were dried and stored for use in porridge and bread, essential staples of the diet. Herbs were dried to create medicinal remedies and flavour food, a practice that became deeply ingrained in British culinary traditions.
In the Middle Ages, food preservation became increasingly important due to the feudal system and the need to sustain large populations through harsh winters. This period saw the development of more advanced drying techniques. Smoking, which combines dehydration with the addition of flavor, became a popular method for preserving meat and fish. Smoking sheds and salting houses became common in rural communities, especially in coastal areas where fish like herring were dried and smoked to create “kipper,” a product that remains a British staple to this day.
Medieval monasteries also played a key role in advancing food dehydration techniques. Monks cultivated extensive herb gardens and dried the herbs for both culinary and medicinal purposes. Dried fruits, such as apples, pears, and plums, were stored for use in pies, puddings, and as natural sweeteners when fresh fruits were out of season.
The 16th and 17th centuries marked a significant shift in food preservation methods in the UK, driven by exploration, trade, and the early stages of industrialization. The drying of food became more systematic and widespread as trade routes expanded and new foods, such as spices and exotic fruits, were introduced to Britain.
Dehydration techniques were refined, and dried goods like raisins, currants, and preserved meats became important commodities. The British Navy played a pivotal role in this period, as dried and salted meats were essential provisions for long sea voyages. Ships carried large quantities of dried fish, beef, and biscuits (known as “hard tack”) to sustain sailors during months at sea.
The Industrial Revolution in the 18th and 19th centuries brought about significant technological advancements, including in the area of food preservation. The development of more efficient drying methods, such as the use of hot air and mechanized drying processes, made dehydrated foods more accessible to the general population.
Factories began producing dried foods on a larger scale, leading to the availability of products like dried peas, soup mixes, and powdered milk. These items became staples in British households, especially in urban areas where access to fresh produce was limited. During this time, the working class relied heavily on these products, as they were affordable, easy to store, and provided a reliable source of nutrition.
The two World Wars in the 20th century had a profound impact on food production and preservation in the UK. During these periods, food rationing and shortages necessitated the widespread use of dehydrated foods. The British government encouraged the public to grow their own vegetables and preserve them through drying and other methods as part of the “Dig for Victory” campaign.
Dried eggs, powdered milk, and dehydrated vegetables became common items in British households during the war years. These products were not only used on the home front but were also sent to soldiers on the front lines, ensuring they had access to essential nutrients even in harsh conditions.
After World War II, with the easing of food shortages and the advent of refrigeration, the reliance on dehydrated foods decreased. However, the practice never fully disappeared and has seen a resurgence in recent years due to the growing interest in sustainable living, emergency preparedness, and health-conscious eating.
Today, dehydrating food is once again popular in the UK, not just for survival purposes but also as a way to enjoy seasonal produce year-round, reduce food waste, and create healthy snacks. Modern dehydrators and improved techniques have made it easier for individuals to dry a wide range of foods at home, from fruits and vegetables to herbs and meats.
Why Dehydrate Food?
Dehydrating food offers numerous advantages, especially for those interested in building a long-lasting, nutritious food store. Here are some key reasons why dehydrating food is a smart choice:
1. Extended Shelf Life
The most significant benefit of dehydrating food is its ability to extend shelf life. By removing moisture, the primary element that supports the growth of spoilage organisms is eliminated. Properly dehydrated fruits, vegetables, and meats can last for months or even years when stored in airtight containers in a cool, dark place. This makes dehydration an excellent option for those looking to create a long-term food supply.
2. Nutrient Retention
Dehydrating food at low temperatures helps to preserve most of the nutrients that can be lost during other food preservation methods like canning or cooking. Vitamins A, C, and other nutrients are retained in dried foods, making them a healthy choice for long-term storage. While some water-soluble vitamins may be slightly reduced, the overall nutrient profile of dehydrated food remains high.
3. Reduced Food Waste
Dehydrating is an effective way to reduce food waste. Surplus produce from your garden or leftovers that might otherwise go bad can be dehydrated and stored for later use. This not only helps in minimizing waste but also ensures that you have a variety of foods available during off-seasons when fresh produce is less accessible.
4. Convenience and Portability
Dehydrated foods are lightweight and compact, making them easy to store and transport. This is particularly beneficial for outdoor enthusiasts, hikers, and campers who need to carry food with them. Additionally, dehydrated foods are easy to rehydrate and incorporate into meals, making them convenient for quick cooking.
5. Cost-Effective
Dehydrating food at home can be more cost-effective than purchasing commercially dried products. By buying in bulk or using your own garden produce, you can save money and ensure that you know exactly what’s in your food, free from preservatives and additives.
How to Dehydrate Food at Home
Dehydrating food at home is a simple process that requires minimal equipment. For this mini guide we will focus on fruits and vegetables. You can dehydrate meat to create jerky and biltong, but for this guide, we’ll keep it to fruits and veggies!
Step 1: Preparation
The first step in the dehydration process is to prepare the food properly. This ensures even drying and better quality in the final product.
- Select Fresh Ingredients: Always start with fresh, ripe produce or high-quality meats. Avoid using overripe, bruised, or damaged items, as they can result in poor-quality dried products.
- Wash and Clean: Thoroughly wash fruits and vegetables under cold running water to remove dirt, bacteria, and pesticide residues. For meats, make sure they are properly cleaned and trimmed of excess fat, as fat can turn rancid during storage.
- Cut Evenly: Slice fruits, vegetables, and meats into uniform pieces to ensure even drying. The thickness of the slices will affect drying time; thinner slices dry faster, while thicker ones take longer. For example, slices of fruits like apples or bananas should be about 1/4 inch thick, while vegetables like carrots can be cut into thin strips or rounds.
Step 2: Pre-Treatment
Pre-treatment is an optional but recommended step that can improve the quality and appearance of dehydrated foods. Depending on the type of food, different pre-treatment methods can be used:
- Blanching: This process involves briefly boiling vegetables and then plunging them into ice water to stop the cooking process. Blanching helps to preserve the colour, texture, and nutritional value of vegetables like broccoli, green beans, and carrots. It also reduces drying time. To blanch, simply boil the vegetable pieces for 2-5 minutes, depending on the type, and then cool them in an ice bath before drying.
- Lemon or Ascorbic Acid Dip: Dipping fruits in a solution of lemon juice or ascorbic acid helps prevent browning caused by oxidation. Mix one cup of lemon juice or ascorbic acid with a quart of water, then soak the fruit slices for 5-10 minutes before draining and placing them on the dehydrator trays.
Step 3: Dehydration Process
With your food prepared and pre-treated, you’re ready to start the dehydration process. You can use a food dehydrator, oven, or even air drying, depending on the food and available equipment.
- Using a Food Dehydrator: A food dehydrator is the most efficient and reliable tool for dehydrating food. It circulates warm air evenly across the trays, ensuring consistent drying. Set the dehydrator to the appropriate temperature which for fruits & Vegetables: 50°C – 70°C (122°F – 158°F) – depending on what type of fruit and vegetables you are using you can go up and down in temperature. More delicate fruit can be dehydrated at the lower range in the 50’s, whilst harder, thicker and more watery fruit may need a higher temperature towards the 70 mark. This is the dehydrator I have used for the past 4 years and it works just as well, if not better than my old industrial size one.
- Single Layers: Arrange the food in a single layer on the dehydrator trays, making sure the pieces don’t touch. Depending on the type of food and thickness of the slices, drying can take anywhere from 4 to 18 hours. Check the food periodically and rotate the trays if necessary to ensure even drying.
- Using an Oven: If you don’t have a dehydrator, an oven can also be used. Set your oven to its lowest setting, typically around 60°C (140°F). Place the food on baking sheets lined with parchment paper and prop the oven door open slightly to allow moisture to escape. This method can take several hours, and you’ll need to check the food regularly.
- Air Drying: Air drying is suitable for herbs, certain fruits, and mushrooms. To air dry, hang the food in a well-ventilated, dry area with plenty of airflow. This method can take several days to a few weeks, depending on the humidity and temperature. It’s best used in dry climates.
Step 4: Conditioning
After the food is dehydrated, conditioning is an important step to ensure that any remaining moisture is evenly distributed across the batch. This helps to prevent spoilage during storage.
- Cooling: Let the dehydrated food cool completely before conditioning. This usually takes about 30-60 minutes, depending on the type and volume of food.
- Conditioning Process: Place the cooled food into a large, airtight container, like a glass jar or large zip lock bag, as long as there is enough room for the food to move when shaken, and close the container. Over the next 5 days, shake the container daily to redistribute the food and monitor for any signs of moisture or condensation. If you notice any moisture, return the food to the dehydrator for further drying. Any sign of mould or contamination and you will need to discard the entire batch. You can also add a bag or two of food grade silica gel to your conditioning container, to help the conditioning process.
Step 5: Storage
Proper storage is crucial to maintain the quality and longevity of your dehydrated food.
- Airtight Containers: Store dehydrated foods in airtight containers such as vacuum-sealed bags, glass jars, or Mylar bags with oxygen absorbers (food grade silica gel). This protects the food from moisture and air, which can lead to spoilage.
- Cool, Dark Place: Keep the stored food in a cool, dark, and dry place. Avoid exposing the containers to direct sunlight or fluctuating temperatures, as this can degrade the food.
- Labelling: Always label your containers with the contents and the date of dehydration. This helps you keep track of how long the food has been stored and ensures that you use older items first.
- Regular Checks: Periodically check your stored dehydrated foods for any signs of spoilage, such as off smells, mould, or changes in texture. If you notice any issues, discard the affected food immediately.
Dehydrating food is a rewarding and practical way to preserve your favorite foods, reduce waste, and ensure a well-stocked pantry year-round. By following the steps of preparation, pre-treatment, dehydration, conditioning, and proper storage, you can create high-quality dehydrated foods that retain their flavor, nutrients, and shelf life. Whether you’re looking to prepare for emergencies, enjoy out-of-season produce, or simply save money, dehydrating is an excellent addition to your food preservation techniques.
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