Freeze-dried raspberries have undergone a dehydration process which removes the water from the fruit whilst retaining the shape and colour of the fruit and intensifying the flavour.
The textured freeze-dried raspberry berries are light and dry, and have different culinary uses to fresh fruit. Try chopping the freeze-dried raspberries and use them to coat chocolate desserts, to flavour sherbets, or even sprinkling over breakfast cereals. The freeze-dried raspberries also make great garnishes for sweet and savoury dishes – the bright colours and tart flavours are a great addition to both sweet and savoury dishes. We love to crumble the berries over raspberry ice cream just before serving.
Benefits of Freeze-Drying raspberries
Raspberries are sometimes referred to as “nature’s candy,” and for good reason. This delicious, fanciful fruit packs nutrition, taste, and aesthetics all into one delightful berry-shaped package. We have been freeze-drying raspberries for a long time, and our commitment to our craft shines in our products. Here, we’ll show you what this berry has to offer a variety of potential food products, and how freeze-drying enhances its properties.
Raspberries offer myriad health benefits. A single cup of raspberries is loaded with 43 percent of our recommended daily vitamin C, plus manganese and fiber. That vitamin C bolsters eye health, manganese contributes to bone health, and the fiber content can help regulate digestion and keep the immune system healthy.
And this robust fruit doesn’t stop there. Most everyone has heard about antioxidants, but many are unclear about what they do. Simply put, these substances contribute to your body’s efforts to fight cancerous tumor growth, as well as reduce inflammation and boost your immune system. Overall, not bad for a berry.
This part is so easy, it almost writes itself. Most of us have tried a raspberry, and are familiar with the delicious, tart taste. Raspberries are the perfect addition to virtually any dessert or breakfast food, and their rich color often provides a beautiful embellishment to the look of a dish.
The freeze-drying twist
Freeze-drying preserves all of the features of the raspberry, from its nutrition to its color. But, there’s an added element the process gives to the berry: intensity of flavor. freeze-drying removes the water but keeps the fruit flavor, leaving behind a berry with concentrated sweetness. The highly-concentrated nature of the finished product is great for adding to baking recipes, as well as products where it can be rehydrated, like yogurts, oatmeal, and cereals. And, there is one more major improvement that comes along with freeze-drying.
Freeze-dried foods are cost effective
Many traditional methods of preservation, like dehydrating, don’t fully remove all the water from fruit. Sometimes, to maintain a quality product, syrups and other additives are brought into the preservation equation. These methods often alter the flavor of a product, and add a crucial component to the cost-balancing process: weight. More weight equals higher cost. Purchasing the relatively light product that freeze-drying produces can save serious cash on a price-per-piece basis.
How to Freeze-Dry raspberries?
We will also present some other methods in freeze-drying if you don’t have a machine for it.
1. Using your freezer
This can be a substitute to the freeze-drying machine if you don’t mind the long process. This long process is estimated to be several weeks at maximum.
To start with it. First, you will need a perforated tray. In choosing the food that you want to freeze-dry, better start with small stuff like fruits. Chop the fruit into small pieces and arrange it neatly on the perforated tray.
Small pieces are preferred because the moisture can easily be removed that way. Choose the freshest ones because when they’re rehydrated, they will still be fresh in the next years.
For the next several hours, the fruit will undergo freezing. However, the long process here will be the sublimation that will take several weeks as stated.
The water will sublimate from solid form into a gas form. Your sliced pieces of fruit will then be thoroughly dried after waiting a long time.
The way to test if your freeze-dried fruit is ready is to thaw it first. If the drying process is not complete, your fruit will turn black after melting. Return it right away to your freezer and wait for a few days.
Test it again by thawing and if doesn’t turn into a black color, that would entail that the freeze-drying process is complete. Your freeze-dried fruit is then ready to be stored in an airtight bag for storing.
2. Dry Ice
Dry ice (or cardice) is carbon dioxide in the solid phase. Freeze-drying food in this method is relatively faster than putting it directly into your freezer. The way to use dry ice is to prepare a large container, twice the size of the food you’re going to freeze-dry.
The food (in this context, fruit) that you should freeze-dry should never be in contact with dry ice, so you need to place it in a sealed plastic bag.
After you placed the food in the plastic bag then into the large container (the bottom base should already have one layer of dry ice), you can now cover the whole container with dry ice. Word of caution for this method is to always wear gloves.
Dry ice should never be melted prematurely, and that’s why you will need to store it in a freezer. Dry ice can make the moisture evaporate from the food because the environment is already at zero humidity.
As the dry ice will sublime and gas will escape, you should punch holes on your large container.
Regularly check your container every 24 hours. You will know the freeze-dried fruit is ready when all the dry ice had sublimed. After that, the freeze-dried fruit is ready for storing.
3. Vacuum Chamber
This process could take one week or more depending on the water content of your fruit.
To start with this, the prepared fruit that you want to freeze-dry should be frozen isolated.
You don’t want ice crystals to form, so don’t open the freezer door until several hours had passed.
Then, removing the fruit from the freezer, place it immediately inside the vacuum chamber.
The recommended temperature and pressure of the chamber should be at least 10⁰C and 120 Torr, respectively. Sublimation process will then occur and may drag on for one week. Test if the freeze-drying is complete and then it’s ready for storage.
4. Freeze-Drying Machine
This is the most expensive method but the duration in preparing the freeze-dried food takes lesser time than all of the methods mentioned above.
A typical freeze-drying machine consists of a freezing coil attached to a compressor, shelves attached to heating units, and a vacuum pump.
To use this machine, place the fruit inside the heated shelves and through the compressor, the temperature is lowered to a freezing temperature. The frozen fruit will then begin sublimation.
This is by the vacuum pump that lowers the atmospheric pressure inside by pumping it outside. The pressure becomes very low that the ice immediately shifts into a vapor form.
The food is undergoing a long process of sublimation that could take a few days at maximum.
To keep your food edible for few more years, you need to store it properly. Storing it in a container without a trace of air should work, like using a vacuum-sealing machine. If not, store it in a plastic zipper and make sure no air enters as you zip it close.
Place it in a cool and dry place away from direct sunlight and the freeze-dried fruit will surely take a long time before decomposing.