Freeze Drying: Tips & FAQs
When I started sharing about my freeze-drying adventures on Instagram, the response was overwhelming! One question kept coming up again and again: “What is the difference between freeze drying and dehydrating?” It’s a great question, and the answer highlights why freeze-drying has become such a popular method for preserving food.
In this article, I’ll explain the difference between freeze-drying and dehydrating and share some helpful tips for beginners. Whether you’re curious about the process, looking for advice on setting up your freeze dryer, or just wondering where to start, this guide has you covered. By the end, you’ll have the knowledge and confidence to start freeze drying at home and preserving food like a pro.
Article Index:
- What is the difference between freeze-drying and dehydrating?
- Why choose freeze-drying?
- Freeze Drying Tips for Beginners
- Choosing the Location for a Freeze Dryer
- Selecting the Right Cart for Your Freeze-Dryer
- Learn how to use the freeze dryer
- Keep It Uniform for Better Results
- Start Simple: Easy Foods to Freeze Dry
- Store Your Freeze-Dried Items Properly
- Where to purchase a Freeze Dryer
- FAQ: Common Questions About Freeze Drying
What is freeze drying?
Freeze drying is a food preservation process that involves freezing food, creating a vacuum, and slowly raising the temperature to remove the moisture. This method retains the food’s flavor, nutrients, and texture far better than traditional methods like dehydrating.
What is the difference between freeze-drying and dehydrating?
What’s the Difference Between Dehydrating and Freeze Drying?
When it comes to preserving food, two popular methods are dehydrating and freeze drying. Dehydrating is an age-old technique that involves removing moisture from food—traditionally by using the sun and air drying meat, fish, and plants. Modern dehydrators accomplish the same goal using heat, often carried by warm air to remove the water in the material.
While this process does extend a food’s shelf life, the use of heat treatment causes about half of its nutritional value to be lost, and can also alter the flavor, texture, and appearance.
Freeze drying, on the other hand, is a more recent innovation that dates back to the early 1900s. It’s a more complex process for removing water content that requires special equipment.
In freeze drying, food is first brought down to extremely low temperatures—around -40°F (-40°C). A vacuum is then created so that, as the temperature slowly rises, the water molecules in the food convert directly into water vapor rather than melting first.
This approach leaves the food’s overall structure, appearance, and nutritional content largely intact, resulting in better taste, texture, and nutrient retention compared to dehydrated foods.
Why choose freeze-drying?
When you look at how freeze-drying compares to traditional dehydration methods, it’s clear why many people prefer it. That’s the technical side of it—but in simpler terms, freeze-dried food tastes better and holds onto more of its original nutrients than dehydrated food.
Because freeze-drying removes moisture at very low temperatures, it locks in flavors and textures far more effectively. And when it’s time to enjoy your stored food, freeze dried items rehydrate quickly and closely resemble the taste, look, and feel of fresh produce, meats, or snacks.
When I got my freeze dryer, I was surprised at how simple the process was. You really do just push a few buttons.
The sensors inside the machine monitor the temperature and internal moisture levels of the food. At the end of the processing, you double check that it is done or if it needs a secondary drying.
I’m so excited to have this way to preserve abundant garden harvests. I’ve already freeze dried bell peppers, hot peppers, roselle, lemons, cilantro and green onions from the garden. I’m looking forward to freeze drying even more garden harvests too.
Freeze Drying Tips for Beginners
Choosing the Best Location for Freeze Dryer
When choosing a spot for your freeze dryer, it’s important to consider more than just convenience. A room that’s too hot will quickly become a problem since the machine generates a lot of heat and won’t run as well if it’s sweltering outside or in the garage during the summer. A cooler space, like a basement or a well-ventilated laundry room, is usually best.
Remember that the machine can run continuously for one to two days and may be noisy, so placing it where the sound won’t bother you makes sense. Also, remember that draining is part of the process, so having a drain pipe, a bucket, or a utility sink nearby will simplify cleanup and help manage any spills as you load and maintain your freeze dryer.
Selecting the Right Cart for Your Freeze-Dryer
It’s also a good idea to have a sturdy cart that can support your freeze dryer, preferably one that can hold at least 250 pounds. Having it on a stable surface keeps everything level and makes it easier to work with. A solid cart reduces the risk of tipping, shifting, or rattling during operation, and it makes it much simpler to move the machine if you need to rearrange your workspace. For example, I use this cart and it’s worked really well for me. The excess liquid drains out into a bucket on the bottom shelf.
Learn how to use the freeze dryer
When you’re ready to dive into the world of freeze-drying, it’s a good idea to start by giving yourself a solid understanding of how your particular machine works. Taking time to read through your manual and checking for any updates on the manufacturer’s website can make a huge difference in your results. Not every freeze dryer is the same, and even models from the same brand may have unique settings or maintenance steps. If you have a Harvest Right freeze dryer, watch the set-up videos on Harvest Right’s website.
Getting familiar with the basics, like proper setup, cleaning procedures, and recommended drying times, will save you a lot of frustration later on. After all, you want to spend more time enjoying your perfectly preserved foods and less time troubleshooting avoidable problems.
Keep It Uniform for Better Results
When preparing your food for freeze-drying, cutting it into small, uniform pieces will help everything dry more evenly. It’s also a good idea to arrange similar foods—or at least foods with similar moisture content—on the same shelf.
Different ingredients dry at different speeds, so mixing items that need a long drying time with those that only need a short one can lead to uneven results. By keeping sizes and types of food consistent, you’ll make the process smoother and end up with better quality, reliably preserved snacks and ingredients.
Start Simple: Easy Foods to Freeze Dry
When you’re just getting started with freeze drying, it’s best to keep it simple. Herbs are an excellent choice—they’re easy to prepare, freeze dry quickly, and give you a chance to learn the basics of using your machine without much effort. Plus, they store beautifully and retain their flavor, making them a great addition to your pantry. Learn more about how to freeze dry herbs in this guide.
Once you’ve mastered the process, you can move on to more adventurous options. For example, freeze-drying something unexpected, like guacamole, is a fun way to see just how versatile your freeze dryer can be. Learn how to freeze dry guacamole in this guide.
Store Your Freeze-Dried Items Properly
How you store your freeze-dried items depends on how you plan to use them. For short-term storage, like when you’ll be opening and closing the containers frequently, half-gallon glass canning jars with leakproof lids work perfectly. They’re easy to access and don’t require oxygen absorbers.
If you’re looking for long-term storage—up to 25 years—mylar bags paired with oxygen absorbers are the way to go. These materials help protect your food from light, air, and moisture, ensuring it stays fresh and ready when you need it.
Don’t have a freeze dryer?
Purchasing a freeze dryer is undoubtedly an investment. My freeze dryer runs almost nonstop, and I’m grateful to have one. I have the medium-size freeze dryer with the premier pump from Harvest Right.
If you purchase a freeze dryer, please consider purchasing through my affiliate link. (It doesn’t cost you more, and I earn a small commission.) Your support helps me continue providing free content on my blog and YouTube channel. Learn more about how to freeze dry here.
Frequently Asked Questions
What foods can I freeze dry?
Almost anything! Popular options include fruits, vegetables, herbs, meats, dairy, and even complete meals. It’s also great for more adventurous items like soups, guacamole, and yogurt. Freeze dried fruits like mangoes are at the top of our list.
Do I need special equipment for freeze drying?
Yes, freeze drying requires a specialized machine designed to freeze the food, create a vacuum, and remove moisture. These machines are an investment, but they make the process easy and efficient.
How long does freeze drying take?
The freeze drying process usually takes 24 to 48 hours, depending on the type and amount of food you’re freeze drying.
Where should I put my freeze dryer?
A cool, well-ventilated space like a laundry room or basement is ideal. Avoid placing it in hot areas like a garage during the summer, as high temperatures can affect the machine’s performance.
How do I store freeze-dried food?
For short-term storage, use glass jars with airtight lids. For long-term storage (up to 25 years), mylar bags with oxygen absorbers are the best choice to protect food from air, light, and moisture.
Does freeze drying preserve food’s nutrients?
Yes, freeze drying retains most of the food’s nutrients, often much more than dehydrating or other preservation methods.
Is freeze drying expensive?
The upfront cost of a freeze dryer can be high, but it’s a long-term investment. Once you have the machine, the cost of freeze drying food is relatively low compared to buying freeze dried foods.
Can I freeze dry liquids?
Yes, you can freeze dry liquids like soups, sauces, and even raw eggs. Freezing them flat in trays before freeze drying makes the process easier.
What are the maintenance requirements for a freeze dryer?
Regularly clean the machine, change the oil (if it’s an oil-based pump), and follow the manufacturer’s maintenance instructions. Proper care ensures your freeze dryer lasts for years.
Can freeze-dried food be rehydrated?
Absolutely! Simply add water to most freeze-dried foods, and they’ll return to their original texture and flavor, often within minutes. The structure of the material doesn’t change.
Is freeze drying safe?
Yes, when done correctly with a quality freeze dryer, it’s a safe and effective way to preserve food. Always follow the manufacturer’s guidelines for best results. Proper freeze drying is very safe.
What’s the shelf life of freeze-dried food?
Properly stored freeze-dried food can last anywhere from 10 to 25 years, depending on the storage method and conditions.
Can I freeze dry at home without a machine?
Technically, it can be done without a machine, but it’s a long, complex process that requires a deep freezer and vacuum pump. A home freeze dryer is much more efficient and user-friendly.
How long do you feel the items in the glass jars will last as opposed to the myler bags with oxygen absorbers?
From what I’ve read, about a year or more. I’m using jars for my short-term storage and using mylar bags for longer term storage.
Does the freeze dry machine require a special electrical outlet or certain wattage?
Check with Harvest Right to see the specific requirements.
@Lu,
The large Harvest Right Freeze Dryer does require a Dedicated 20 Amp Circuit.
The Small and Medium can use an existing 15 Amp Circuit, but I would not put it on a circuit that has other appliance’s on it.
Thanks for the clarification.
@Lu, it depends on which one you get. The small and medium models don’t. The large one requires a dedicated 20 amp circuit and a 5/20 plug.
How do you keep a record of what you are freeze drying and what info do you record? Do you weigh every pan? Is it important to record how long it took to dry? Any thing else?
It depends on how detailed you want to be with your records. Keep track of whatever information you feel is important to record and remember.
Thanks for all of the information, Angela. I learned a lot.
I guess I’ll stay with dehydrating for now. The freeze drying machine is
a little pricey for me.
I just got my frizz drier. I got Pinterest and found your post. Did my peppers first and they turned out great. Thanks
That’s great. Enjoy!
Contemplating purchase of freeze dryer for shelf stable storage of our abundant garden harvests.
Do you have any ideas about freeze drying bell or poblano peppers that have been prepped for stuffing or eggplant slices for future casseroles?
Appreciate any advice – thanks!
Peppers become crumbly once processed. It would be tough to keep the shape. I love freeze dried peppers, but I usually slice them. They are a tasty snack. I haven’t tried freeze drying eggplant.