Freeze Drying Foods and Long Term Storage
Freeze drying is a fascinating preservation method that allows us to retain the flavor, texture, and nutritional value of foods while extending their shelf life significantly. By removing moisture from foods in a frozen state, freeze drying prevents the growth of microorganisms and enzymatic reactions that cause spoilage. Let’s explore the world of freeze drying, exploring the wide range of foods suitable for this technique and providing insights on proper storage using mylar bags or glass jars.
The Art of Freeze Drying: The Process & Benefits
Freeze drying, also known as lyophilization, is a preservation technique that involves freezing food items and then subjecting them to a vacuum environment. The process consists of three main stages: freezing, sublimation, and desorption. During freezing, food is rapidly frozen to maintain its cellular structure. Sublimation involves converting frozen water directly into vapor without transitioning into a liquid state. Lastly, desorption removes the vapor from the system, leaving behind freeze-dried food with minimal moisture content.
Freeze drying offers several benefits. First and foremost, it preserves the original taste, aroma, and texture of the food. Unlike other preservation methods that can alter these characteristics, freeze drying allows for a remarkably high retention of flavor and maintains over 90% of the food’s nutritional value. Additionally, freeze-dried foods are lightweight, making them ideal for backpacking, camping, and emergency preparedness. Moreover, freeze drying retains the nutritional value of foods, including vitamins, minerals, and antioxidants.
Foods Suitable for Freeze Drying
A wide range of foods can be freeze dried, including fruits, vegetables, meats, dairy products, herbs, and even complete meals. I buy most of my favorites from Azure in bulk which saves me time and energy. Here are some examples:
Fruits: Berries, apples, pineapples, mangoes, and bananas are commonly freeze-dried. They can be enjoyed as healthy snacks or added to cereals, smoothies, or desserts.
Vegetables: Peas, corn, green beans, carrots, and bell peppers are excellent candidates for freeze drying. They can be rehydrated and used in soups, stews, or as side dishes.
Meats: Chicken, beef, pork, and seafood can be freeze dried to create long-lasting protein sources. Freeze-dried meat is often used in camping or emergency food kits.
Dairy products: Milk, cheese, yogurt, and ice cream can be freeze dried, preserving their flavors and extending their shelf life.
Herbs: Herbs such as parsley, basil, cilantro, and dill can be freeze dried to retain their vibrant colors and flavors. They can be easily crushed and used in recipes.
While many foods can be freeze dried, some items are not suitable due to their high fat or oil content, which can lead to rancidity. Examples include avocados, olives, and fatty cuts of meat. Additionally, foods with high water content, such as watermelon or cucumber, may not yield satisfactory results when freeze dried.
Proper Storage: Mylar Bags & Glass Jars
Once foods are freeze dried, proper storage is essential to maintain their quality and longevity. Two popular options for storing freeze dried foods are mylar bags and glass jars.
Mylar bags:
Mylar bags are a common choice for long-term storage of freeze dried foods. Follow these steps for optimal storage:
Select high-quality mylar bags with a thickness of at least 5 mil to prevent moisture and oxygen permeation.
Fill the bags with freeze dried foods, ensuring they are tightly sealed with a heat sealer.
Place an oxygen absorber packet (containing iron and salt) into each bag to remove any remaining oxygen. This helps prevent oxidation and spoilage.
When it comes to using oxygen absorbers for food storage, choosing the right size is essential to ensure optimal results. For a gallon-sized bag, a commonly recommended oxygen absorber size is 300cc to 500cc, depending on the density of the food being stored. This size is suitable for removing excess oxygen and maintaining freshness in larger volumes of food. For a 5-gallon container or bag, a larger size oxygen absorber, typically in the range of 1500cc to 2000cc, is recommended due to the increased volume of air that needs to be absorbed. Finally, for quart-sized bags, a smaller oxygen absorber in the range of 50cc to 100cc is typically sufficient to remove oxygen effectively. It's important to follow the manufacturer's guidelines and consider the specific requirements of the food being stored to determine the appropriate size of oxygen absorber for each container or bag.
Label the bags with the contents and date of packaging.
Store the mylar bags in a cool, dark, and dry place, away from direct sunlight, extreme temperatures, and moisture for 20+ years.
Glass jars:
Glass jars provide an excellent alternative for storing freeze dried foods, especially for shorter-term storage or frequently accessed items. Here's how to properly store freeze dried foods in glass jars:
Choose clean, airtight glass jars with rubber gaskets and metal clamps or screw-top lids.
Fill the jars with freeze dried foods, leaving minimal headspace to reduce exposure to air.
Close the jars tightly to create an airtight seal - you can add an oxygen absorber in the jars to increase shelf life.
Label the jars with the contents and date of packaging.
Store the glass jars in a cool, dark, and dry pantry or cupboard, away from moisture and sunlight for 1-2 years.
Remember that regardless of the storage method, it's essential to regularly inspect the freeze dried foods for signs of spoilage, such as discoloration or an off odor. If any signs of deterioration are present, discard the product to ensure food safety.
Freeze drying is a remarkable preservation technique that allows us to enjoy the natural goodness of foods for an extended period. With the ability to retain flavor, texture, and nutritional value, freeze dried foods are a valuable addition to our kitchens, camping trips, and emergency preparedness kits. By understanding the freeze drying process, identifying suitable foods, and employing proper storage methods using mylar bags or glass jars, we can maximize the longevity and quality of our freeze dried treasures. So, embark on your freeze drying adventure and experience the wonders of preserving nature's bounty in a whole new way.