We now have a freeze dryer. Sugar does not freeze dry. It is hydroscopic (holds onto water molecules). To test if a food containing a significant or unknown amount of sugar will freeze dry, it is frozen first.
There is a salsa that we really like that I was interested in freeze drying so I decided to do a test run. While I was at it, I thought I would test a BBQ sauce and a ketchup that we like. I knew that both of those might be problematic due to a potentially high sugar content.
First I put small amounts in a silicon mold and froze them. The salsa made beautiful little cubes. The BBQ sauce almost froze solid and the ketchup was the consistency of very thick pudding.
Onto a tray for freeze drying with the salsa. What to do with the other two? I did not want to throw them away but they were not going to freeze dry. They were going to explode when it pulled a vacuum and make a huge mess.
Scoop them out and put them back. The mold was small. A scraper would not fit in it but my pointer finger would. I scooped them out with that poor finger. Yes, it started to feel really cold and hurt but it was only a little bit of product so I pushed through and finished.
Washed my hands. Oops. My finger felt funny. In fact by now it felt like it had a shot of Novocain. I could not feel anything I touched with it. When I felt it with my other hand, the finger tip was solid. No give. Frozen solid.
<sigh> Frost bite. Boy does it hurt! It hurts for days. No one I talked to knew what I should expect. Would my finger tip fall off? How long would it hurt? It was red and hot for several days. In fact it is just now starting to be a normal temperature compared to the other fingers on that hand.
Moral of the story - sugar burns at both high and low temperatures. Handle it with care.