FAQs

General Questions

Q: What is freeze drying?
A: Freeze drying, also known as lyophilisation, is a process that removes moisture from food or other items by freezing them and then using a vacuum to turn the ice directly into vapour, skipping the liquid phase. This preserves the structure, flavour, and nutrients of the product.

Q: What can I freeze dry?
A: You can freeze dry a variety of foods, including fruits, vegetables, meats, dairy products, complete meals, and even desserts. It’s also used for non-food items like flowers, pet food, or pharmaceutical products.

Q: How long does freeze drying take?
A: The freeze-drying process typically takes between 20 to 40 hours, depending on the type and amount of food being processed.

Q: What are the benefits of freeze drying food?
A: Freeze drying preserves up to 97% of nutrients, extends shelf life for up to 25 years (when properly stored), and retains the original taste, texture, and appearance of food.

Q: Is freeze-dried food the same as dehydrated food?
A: No. Freeze drying removes about 98-99% of moisture, while dehydration removes around 90-95%. Freeze-dried food retains more nutrients, flavour, and texture compared to dehydrated food.

A black Leosmak food dehydrator with a digital display on top, surrounded by glass jars filled with various dried foods like fruits, vegetables, and herbs, in a kitchen setting.

Using a Freeze Dryer

Q: How does a freeze dryer work?
A: A freeze dryer works in three main steps:

  1. Freezing the food to very low temperatures (-40°C or colder).

  2. Creating a vacuum to lower the air pressure.

  3. Applying controlled heat to sublimate the ice into vapour, leaving the food dry.

Q: Are freeze dryers easy to use?
A: Yes, modern freeze dryers are user-friendly. Simply load the trays, start the machine, and let it run. Many machines have automatic settings for different types of food.

Q: How much food can I freeze dry at once?
A: The capacity depends on the size of the freeze dryer. Small home models typically handle 2-3kg per batch, while larger models can handle up to 8-10kg.

Q: Do freeze dryers require special maintenance?
A: Yes, routine maintenance is needed, such as cleaning the machine, draining the vacuum pump oil (if applicable), and checking for proper seals.

Industrial food dehydration oven or dryer with a circular door and multiple racks inside.
Four bowls of sliced vegetables and greens arranged in a vertical line on a wooden surface.
A mason jar with a pink berry smoothie and two striped straws, an open glass jar of berry powder, and fresh mixed berries on a wooden surface.

Storage and Shelf Life

Q: How do I store freeze-dried food?
A: Store freeze-dried food in airtight containers, such as Mylar bags with oxygen absorbers or vacuum-sealed jars, to prevent moisture and oxygen exposure.

Q: How long does freeze-dried food last?
A: When stored properly, freeze-dried food can last up to 25 years, making it ideal for emergency preparedness or long-term storage.

Q: Can I rehydrate freeze-dried food?
A: Yes, simply add water to rehydrate the food. The amount of water needed depends on the food type, but it generally rehydrates quickly and returns to its original texture.

Stainless steel industrial food processing machine with a round cylindrical chamber, a door with a handle, vents on the side, and wheels for mobility.
Laboratory sterilizer or autoclave with a digital control panel, open door, and a cooling or vacuum pump attached.
Juice pasteurizer machine on kitchen countertop surrounded by jars of sliced bananas, raspberries, raspberries, and strawberries, with bowls of strawberries and raspberries, a bunch of bananas, pineapple, and green beans nearby.