That first bite of a freeze-dried Skittle is without a doubt a WOW moment. The science behind the process is fascinating. The flavor, texture and crunch of freeze-dried candy are the result of a unique process that happens in the freeze dryer.

......................................................................................................................................................................................

How we freeze dry our candy?

Freeze drying is done in a Freeze dryer it cannot be done in a dehydrator or an oven.

The process begins by cooling food down to -20 degrees Celsius. That’s cold !!

Once the food is frozen, the air in the chamber is removed using a vacuum pump, leaving the food under very low pressure. Lowering pressure also lowers the temperature water and other chemicals change their state. With freeze drying, the ice is under such low pressure it will evaporate before it’s warm enough to melt.

The temperature of the freeze-dryer chamber is slowly warmed to –10 degrees. As the ice crystals in the food change, they gasify and disperse. This process can be repeated several times.

During the final stage, the temperature of the chamber is slowly elevated to 120 degrees. This ensures that most of the remaining moisture has evaporated. This way, 98 to 99% of the moisture is removed in freeze-drying.

......................................................................................................................................................................................

Why does candy puff up when it is freeze dried?

Freeze dried food does not typically shrink like dehydrated food does. Most foods maintain the shape it had before freeze drying. So why does candy puff up so much?

Put simply its due to PRESSURE, VOLUME, AND TEMPERATURE

When you cool candy and the water inside to -50 degrees, the surrounding pressure will decrease a bit, but the volume doesn’t change that much. On the other hand, when you reduce the pressure to almost nothing and start to raise the system's temperature, that’s when the candy puffs. The newly gasified water expands quickly, and so does the candy.

The freeze dryers that are being manufactured today have an update specifically for Candy. The temperature is raised at the beginning up to as high as 150 degrees making the sugars softer before the rest of the process takes place making candy light fluffy crispy and crunchy.