Why Does Freeze-dried Candy Puff Up?

Freeze-dried candies are all over the internet, and for good reason. As of late, freeze-dried candy manufacturers have been flooding the market, freezing and selling any and all types of candies they can find online. Light, playful, and freeze-dried—all these words are used by people to describe their impression of these candies. 

But why is it so fun to taste? For the simple reason that it puffs to double its usual size! This isn’t less than any magical trick. Now, you might ask how a normal candy, or any candy for that matter, gets double in size. Well, that’s the trick. A lot of interesting research backs the freeze-drying process. 

To explain it simply, the pressure within the vacuum machine used to make freeze-dried candy causes it to puff up. The majority of candies are classified as semi-solid, so when the water gasifies via sublimation, they have no way of preventing themselves from inflating like balloons. 

The Freeze-Drying Process Explained

One way to keep food and other perishables from going bad is to freeze-dry them, a process also known as lyophilization. By lowering the inside pressure, the frozen water in the material can sublimate or go straight from solid to gas without ever having to transit through the liquid phase in freeze-drying, in contrast to more conventional drying procedures.

There are typically three primary phases in the freeze-drying process:

Freezing

The candy is often frozen at very low temperatures, typically ranging from -50°C to -80°C (-58°F to -112°F). The water content in the candy is solidified at this stage.

Sublimation (Primary Drying)

It is also known as sublimation. It involves putting the frozen candy in a vacuum chamber with drastically reduced pressure. At these low pressures, the ice sublimates, or turns into vapour rather than a liquid. A little heat is administered to facilitate this procedure. At this point, the candy has lost almost all of its water content.

Secondary Drying

Finally, the candy undergoes secondary drying, also known as desorption, by slowly raising the temperature while keeping the vacuum in place. This process removes any residual moisture. At this point, the candy should have less than 2% moisture, meaning it has fully dried and you can also buy peelable mango gummies candy.

What Makes the Freeze-Dried Candy Puff Up?

Here are some things that are responsible for fluffing up your favorite candy these days:

Water Content

A high water content and a structure are characteristics of most candies. This is particularly true of gummy candies and marshmallows. During the first step of freeze-drying, this water expands as it freezes. The creation of ice crystals causes the candy's structure to become stiff.

Sublimation

During the first drying phase, ice crystals leave behind little air pockets as they sublimate into water vapor. This process is known as expansion. The structure stretches to cover the space left by the sublimated water, and the candy expands due to these air pockets. The candy is grown even more under low pressure in the vacuum chamber as it expands into the available area.

Air

Because of the freeze-drying process, the candy becomes very porous, trapping air inside. The air pockets trapped inside the candy during sublimation give it a puffy look. The trapped air enhances the crunchy texture and light, airy feel of the candy.

Elasticity

The amount of puffing depends on the candy type being freeze-dried. The elasticity that gives gummy candies and marshmallows their distinctive shape lets them stretch and expand as they freeze-dry. These candies are able to withstand the expansion that occurs during ice sublimation because they are structurally flexible, thanks to the gelatin or other gelling agents used.

Temperature

How much the candy puffs up is heavily dependent on the temperature and pressure parameters used during the freeze-drying process. Lower temperatures and pressures promote more successful sublimation and produce bigger air pockets inside the candy, resulting in greater expansion.

FAQs

What makes the freeze-dried candy puff up?

Since freeze-drying naturally causes a loss of water, the resulting candy is more concentrated and has a sweeter, richer flavor than the original. The candy could "explode" or "puff up," changing its appearance from the original. You can expect your candies to taste even better after freeze-drying them.

How are freeze-dried candies different from regular sweets?

A special way to preserve sweet or sour candies is by freeze-drying them. Even though this approach speeds up the rehydration process and adds flavor, it has no effect on the candy’s nutritional value. Another benefit of freeze-dried candies is their extended shelf life. You can enjoy them for months to years depending on how your store it.