I remember the first time I tried a Thrive freeze dried grape. Before opening the container I thought, isn't it just going to be like a raisin? When I actually opened the can and picked up a crunchy flat-ish grape piece, I wondered why? Why isn't it like a raisin? Why is it crunchy? Why is it different from dehydration? Why is it relevant? What actually happens when something is freeze dried? In this post we'll address these questions and help define what happens when food is freeze dried. We will also touch on why we can benefit from freeze dried food.
(Image 1. pantry can of Thrive freeze
dried grapes.)
What is freeze drying?
Freeze drying is the process of preservation by rapid freezing followed by a drying treatment in a high vacuum chamber. It maintains structure, nutrition and flavor. It pulls out almost 100% of the water making it a great resource for long-term storage.
(Image 2. Industrial freeze dryer.)
A freeze dryer will work in 3 phases to freeze dry successfully:
The first phase is rapid freezing. Freezing rapidly helps prevent the ice crystals from getting too large and damaging the cell walls.
The second phase is the primary drying phase, also known as sublimation. Sublimation occurs when lowering the vacuum pressure and adding heat to the food, which causes the frozen water from phase one to immediately transition into gas and evaporate from the food. At this point most of the water has been removed from the food- about 95%!
The third phase is the secondary drying phase, or adsorption. The remaining 5% of water is ionically bound to molecules in the food. This second drying phase is done by continued pressure and increasing the heat to break those bonds and remove the last bit of water.
The science of freeze drying is really cool and so different from dehydration. Dehydration has been around for ages and involves removing as much moisture as possible in the sun or an oven. It uses much more heat and breaks down the molecules of the food. While the concept of drying for preservation is the same, dehydration only removes, at most, about 95% of the moisture, while freeze drying removes 98-99%. (Image 3. Food prepped for freeze drying.)
Why is freeze drying relevant to us?
(Image 4. My latest order of freeze-dried food.)
Freeze drying has only been around since the early 1900's and wasn't known internationally until World War II where they used it for medical purposes. Now it is rapidly rising in popularity, especially in the food processing market. People are looking for meal solutions from their busy schedules. Rapid urbanization and a popularity of preserved foods has fed this boom in freeze drying. I think it is worth investigating the benefits freeze dried food can offer me, with the growth it is estimated to have in the future.
Freeze drying retains 97% of the nutrients. Not only is this an A+ percentage but it is substantially higher than that of other preservation methods. The heat involved with other processing methods destroys much of that nutritional content leaving only around 40% in canning and 60% in dehydration. All the fiber remains intact after freeze drying as do probiotics, antioxidants, and other phytochemicals that provide protective health benefits.
(Image 5. Visual comparison of percent nutritional value maintained.)
Freeze dried food holds most, if not all, of the original products' flavor and texture. Freeze drying won't shrink or make your food chewy. The molecular structure of the food is maintained. When you add water back to rehydrate it, then it will feel and taste like the day it was first cooked. Compare that with dehydration, which changes the food's texture and flavor. Which would you prefer?
(Image 6. Strawberries before and after freeze drying.)
The 99% of moisture removed gives freeze dried food a shelf life of 25-30 years. The (freeze dried) cherry on top, is that you can freeze dry almost any food. So that delicious 25-30 year shelf life can include basically all your favorite foods. Thrive Life Food provides anything from shrimp and onions to cheese and berries. After 30 years on the shelf, you can open that can of freeze-dried strawberries and they will taste like you picked them from the garden that morning. Kind of amazing when you think about it.
To sum up my freeze-dried grape experience. It was colorful, sweet and very crunchy. More like candy than a piece of fruit. But that's all it was, a fruit. A grape that had been rapidly frozen, placed in a pressure chamber two times to zap all of its water and left for me to enjoy as a crunchy sweet treat. And not only did it look more appealing than a raisin, but it tasted better too.
(Image 7 and 8. Visual comparisons of freeze-dried and dehydrated (raisin) grapes.)
But where did I get a can of freeze-dried grapes? They aren't exactly lining the supermarket shelves. I do not own a freeze dryer. Freeze-drying is a fairly complex undertaking that requires expensive, specialized equipment, as we have read. Not to mention freeze drying at home with your own dryer can make the exact shelf life a little uncertain. I don't have an extremely large garden with a lot of leftover produce. Majority of things I would freeze dry I would have to purchase from the store. With all of that in mind, I'm not really interested in owning my own freeze dryer.
I still want freeze dried food at my house. It just makes a lot more sense for us to purchase freeze dried food from Thrive Life. And we still get to enjoy all the benefits it provides. Head to our website and you can see the wide variety of options. And once you taste some you will see exactly why it is growing in popularity.
(Image 9. Me with some freeze dried food I love.)
Sources
https://www.millrocktech.com/lyosight/lyobrary/what-is-a-freeze-dryer/
https://en.m.wikipedia.org/wiki/Sublimation_(phase_transition). March 17, 2023.
https://mountainhouse.com/blogs/camping/freeze-dried-vs-dehydrated-food-for-the-outdoors?
https://www.masterclass.com/articles/how-long-does-dehydrated-food-last
https://empiredrying.com/freeze-drying-equipment-market/
https://www.globenewswire.com/news-release/2022/08/18/2500990/0/en/The-Global-Freeze-dried-Food-Market-size-is-expected-to-reach-106-6-billion-by-2028-rising-at-a-market-growth-of-7-4-CAGR-during-the-forecast-period.htm
https://oureverydaylife.com/534805-does-freeze-drying-affect-nutrition.html. March 17, 2023
https://ezprepping.com/freeze-dried-food-healthy/