Basic food preservation
Basic food preservation techniques such as drying and salting are essential skills for sustainable survival. These methods extend the shelf life of food, prevent spoilage, and reduce the risk of disease caused by contaminated or rotten food. This section provides comprehensive guidance on how to properly dry and salt food, the science behind these methods, suitable foods for preservation, and practical tips for long-term storage.
Introduction to Food Preservation
In a post-collapse or survival scenario, access to fresh food is often limited or unpredictable. Preserving food allows you to store surplus harvests or hunted game safely for extended periods, ensuring a steady food supply and reducing waste. Basic preservation methods like drying and salting require minimal equipment and can be performed with natural resources, making them ideal for sustainable survival.
Food preservation works primarily by inhibiting the growth of microorganisms such as bacteria, yeasts, and molds, or by slowing down enzymatic reactions that cause food to spoil. Drying removes moisture, which microbes need to grow, while salting creates an environment hostile to microbial life by drawing out water through osmosis.
Drying Food
Principles of Drying
Drying, also known as dehydration, is one of the oldest and simplest methods of food preservation. It involves removing water content from food to levels low enough to prevent microbial growth and enzymatic activity. Most bacteria and molds require a water activity (aw) level above 0.6 to thrive; drying reduces aw below this threshold.
Suitable Foods for Drying
- Fruits: Apples, apricots, berries, peaches, pears, plums, and grapes (raisins).
- Vegetables: Tomatoes, peppers, mushrooms, green beans, peas, corn, and leafy greens.
- Meats: Lean cuts of beef, venison, fish, and poultry can be dried as jerky.
- Herbs: Basil, thyme, oregano, rosemary, and parsley.
Preparation for Drying
- Cleaning: Wash all produce or meat thoroughly to remove dirt and contaminants.
- Cutting: Slice fruits and vegetables into uniform thin pieces (about 1/4 inch thick) to ensure even drying.
- Blanching (for vegetables): Briefly boiling vegetables before drying can deactivate enzymes that cause spoilage and preserve color and nutrients.
- Marinating or seasoning (optional for meats): Use salt, spices, or marinades to enhance flavor and preservation.
Drying Methods
Sun Drying
Sun drying is the most accessible method but requires hot, dry, and sunny weather with low humidity.
- Setup: Use a clean, elevated drying rack or screen covered with fine mesh to keep insects away.
- Process: Arrange food in a single layer with space between pieces for air circulation.
- Protection: Cover with cheesecloth or netting to protect from insects and dust.
- Duration: Depending on weather and food type, drying can take 1 to 5 days.
- Considerations: Avoid drying in humid or rainy conditions to prevent mold growth.
Oven Drying
Oven drying is a controlled method suitable when sun drying is not feasible.
- Temperature: Set oven to the lowest possible temperature, ideally between 50°C to 60°C (120°F to 140°F).
- Setup: Place food on wire racks or baking sheets lined with parchment paper.
- Airflow: Keep the oven door slightly ajar to allow moisture to escape.
- Duration: Typically 6 to 12 hours depending on food thickness and moisture content.
- Monitoring: Check periodically to avoid over-drying or burning.
Dehydrators
If available, electric dehydrators provide consistent temperature and airflow, making drying efficient and reliable.
- Temperature: Usually set between 50°C to 60°C (120°F to 140°F).
- Arrangement: Place food in a single layer on trays.
- Time: Varies from 4 to 24 hours depending on food type.
Signs of Properly Dried Food
- Fruits: Should be pliable but not sticky or moist.
- Vegetables: Should be brittle or leathery.
- Meat jerky: Should be dry, firm, and slightly flexible without any moist spots.
Storage of Dried Food
- Store dried food in airtight containers such as glass jars, vacuum-sealed bags, or heavy-duty plastic bags.
- Keep containers in a cool, dark, and dry place to maximize shelf life.
- Properly dried and stored foods can last from several months to over a year.
Salting Food
Principles of Salting
Salting preserves food by drawing moisture out through osmosis, creating an environment inhospitable to bacteria and fungi. Salt also interferes with microbial enzyme activity and metabolism.
Types of Salt Used
- Coarse salt: Preferred for curing meats and fish due to its slow dissolving properties.
- Fine salt: Used for brining and seasoning.
- Sea salt or kosher salt: Commonly used for preservation; avoid iodized salt as additives may affect preservation.
Suitable Foods for Salting
- Meats: Beef, pork, fish, poultry.
- Vegetables: Cucumbers (for pickling), cabbage (for sauerkraut), and other firm vegetables.
Salting Methods
Dry Salting (Curing)
- Process: Rub salt liberally over the surface of the meat or fish.
- Layering: Place salted food in a container, layering with additional salt.
- Duration: Cure for several days to weeks depending on thickness and type of food.
- Draining: Salt draws out moisture, which collects as liquid; drain regularly to prevent spoilage.
- Rinsing: After curing, rinse off excess salt before cooking or further processing.
Brining
- Preparation: Dissolve salt in water to create a brine solution (typically 5-10% salt by weight).
- Submersion: Fully submerge food in the brine.
- Duration: From several hours to days depending on food type and size.
- Refrigeration: Keep brining food cool to prevent bacterial growth.
- Usage: Brined foods can be cooked directly or further dried or smoked for preservation.
Combination with Smoking or Drying
Salting is often combined with smoking or drying to enhance preservation and flavor. Salt cures the food, while drying or smoking removes moisture and adds antimicrobial compounds.
Additional Preservation Techniques Related to Drying and Salting
Smoking
Smoking exposes food to smoke from burning wood, which deposits antimicrobial compounds and dries the food. It is commonly used with salted meats and fish.
- Cold smoking: Performed at temperatures below 30°C (86°F), mainly for flavor and preservation.
- Hot smoking: Performed at 52-80°C (125-175°F), cooks and preserves food simultaneously.
Fermentation
Fermentation uses salt to create an environment where beneficial bacteria thrive, producing acids that preserve food. Examples include sauerkraut and kimchi.
Practical Tips for Successful Preservation
- Cleanliness: Always use clean tools, containers, and hands to prevent contamination.
- Uniformity: Cut food into uniform sizes for even drying or curing.
- Monitoring: Regularly check drying or curing food for signs of mold or spoilage.
- Humidity control: Avoid high humidity environments; use desiccants or airtight containers for storage.
- Labeling: Mark dates and contents on stored food to track shelf life.
- Testing: Before long-term storage, test a small batch to ensure preservation method effectiveness.
Nutritional Considerations
- Drying concentrates nutrients but may reduce some heat-sensitive vitamins like vitamin C.
- Salting increases sodium content; consume salted preserved foods in moderation.
- Combining preservation methods with a varied diet ensures balanced nutrition.
Summary
Mastering basic food preservation through drying and salting is vital for sustainable survival. These methods extend food usability, reduce waste, and provide reliable nutrition when fresh food is scarce. By understanding the science, preparation, and storage techniques, survivors can maintain a stable food supply and improve resilience against starvation and disease.
For further knowledge on growing food to preserve, see Growing basic crops. For safe water sourcing to complement preserved food consumption, refer to Clean water sourcing and purification.
