If you are curious about the freeze-drying process but are put off by the expensive price of commercial freeze dryers, you might be excited to know that you can build your own.
While building your own DIY freeze dryer can seem daunting, once you understand how freeze-drying works you will find that it’s entirely possible. If you want to know what it takes, here are three freeze dryers you can make at home.
Why Build a Home Freeze Dryer?
The biggest drawback of freeze-drying food is how incredibly expensive commercial machines are. That’s why building your own DIY freeze dryer might just be worth your time and effort.
With a little patience, you can avoid the high price tag of commercial freeze dryers, which start at $2,500 and reach as high as $6,000 depending on the size. Luckily, there are a few project guides out there to help you build your own freeze dryer at home. Soon you will be freeze-drying all your favorite foods which, when stored correctly, can last up to 25 years.
If you choose to build your own freeze dryer at home, you can look forward to preserving all kinds of food for short- and long-term storage. From berries and fruit to meat and entire leftover meals, freeze-drying is a process that doesn’t change the shape, size, or color of your preserved food.
You can use your DIY freeze dryer to prepare meals for hiking, store your extra garden produce, or preserve meats and veggies that you buy on sale from the supermarket. Whatever you intend to use your freeze dryer for, building your own DIY freeze dryer can save you a significant amount of money.
1. Easy Home Freeze Dryer
You might have heard about astronaut ice cream; it’s one of the most famous examples of freeze-dried food. Developed for space travel, astronaut ice cream is real ice cream that has had all the moisture removed through the freeze-drying process. You can buy this space treat from the website Astronaut Foods, but of course, you can replicate it at home if you build your own home freeze dryer.
The easy part of this project is the choice of materials. You can find everything you need to build this freeze dryer on websites such as Amazon, or from a local hardware store. Some core components include a couple of vacuum chambers, a regular cooking pot, dry ice, Styrofoam, and denatured ethanol (aka methylated spirit). You will need minimal tools to assemble these parts together. At one point you will need a spade bit and drill to widen a hole, but otherwise, most parts are fixed with bolts and tube clamps that can be tightened with a wrench.
Most importantly, you will need a vacuum pump and a digital gauge to make sure you can reach a low enough pressure for sublimation to occur. In simple terms, what this means is that the frozen water inside the food turns into vapor, without going through the liquid stage first. For a walk-through of the science as well as exactly how to build yourself a freeze dryer, this project video will have you covered.
2. Cheap DIY Freeze Dryer
Unsure if you want to tackle building a freeze dryer by yourself? Then take a quick five-minute break to watch this video. It briefly covers the science behind freeze-drying while also giving you an overview of the parts and construction needed for this project. Most parts can be bought online or at a hardware store; at the time of posting the video, they cost less than $200.
Once again you will need a vacuum pump that can reach extremely low pressures. You will also need foam insulation, dry ice, and some strong glass bowls to create the vapor trap, all of which are connected with tough plastic pipes and metal fittings. While the process involves using a drill press which you may not have ready access to, the cost is, without a doubt, more affordable than a commercial freeze dryer.
3. Simple Home Freeze Dryer
Finally, if you want to try freeze-drying food without purchasing specialized equipment, there is a way. This project on Instructables was designed by someone who works in a lab with desiccators, aka those small packets of beads that are included in the packaging to keep products dry. Using desiccators to draw moisture, and a freezer to lower the temperature, you can effectively freeze-dry your food—it just takes a bit longer.
In place of a vacuum pump, you simply need a wine-saver hand pump to lower the pressure inside the container you want to use. Inside this container, place the desiccators at the bottom to adsorb moisture, with the food you want to freeze-dry placed on the top (a divider is placed in between). To mimic the low temperatures required for the process to work, place the low-pressure container in the coldest part of your freezer. After a day, check if you need to replace the desiccant inside and then re-vacuum the container.
It takes about a week to freeze-dry, which is much longer than a commercial machine: the latter can freeze-dry items in 24 hours. However, for this incredibly cheap and easy-to-do freeze-drying process, it’s definitely worth trying out.
Build Your Own Freeze Dryer
If you are a keen DIY enthusiast then building your own homemade freeze dryer is a great project for the weekend. Especially if you have experience with machinery like vacuum pumps and press drills, building a freeze dryer is a far more affordable option than buying a commercial unit.
Even if you don’t normally work with special power tools, you can freeze-dry food with nothing much more than a wine-saver hand pump and the clever use of desiccants and a freezer. With the help of science and the design skills of DIY makers, building your own freeze dryer is completely doable.
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