Hard caramel in ice cream

[Ava]

I recently made some cinnamon ice cream and mixed in toasted marshmallows and hard, broken up caramel (made with just sugar). After a few weeks it appears most of the caramel pieces have 'disappeared' and there is now a liquid layer at the bottom of the tub which, on tasting, seems to be caramel with some ice cream mixed in.

 

I don't understand how this has happened - I tried it after seeing how David Lebovitz's caramel ice cream recipe has hard pieces of caramel in it, so obviously it should actually work. Why has mine... melted? In the freezer, too?

 

Very much hoping the answer isn't that there's a problem with the freezer...

[lesliec]

I'm far from an expert on this, but I do know that high sugar content = difficult to freeze. Could be your caramel pieces just dropped through the ice cream, melting a little of it and dissolving as they went, until you ended up with the 'syrup' layer you describe.

 

It would be good if some of the experts (paging @JoNorvelleWalker) could weigh in with a more informed opinion.

[KennethT]

Sugar absorbs moisture like crazy, so when the hard caramel was surrounded by water (the ice cream) it absorbed it, and became softer and more liquid over time.

[pastrygirl]

Yep, exactly what Kenneth said. Your caramel was just sugar, and would turn to goo over time even left out in a humid kitchen. 

 

A toffee made with butter should last a little longer with the fat there to interfere with water absorption. 

[Lisa Shock]

Freezer temperatures are not cold enough to stop the motion of diffusion. (you'd need to be storing your ice cream inside a dewar of liquid nitrogen to accomplish that) Sugar is very hygroscopic, the only way to be able to store chunks of it in ice cream for any period of time would be to coat the chunks in wax or fat like cocoa butter. Think about commercial ice creams, there are no hard candy type chunks in any commercial ice creams. Premium ice cream makers even enrobe nuts in chocolate to prevent sogginess.