Jump to content
  • Welcome to the eG Forums, a service of the eGullet Society for Culinary Arts & Letters. The Society is a 501(c)3 not-for-profit organization dedicated to the advancement of the culinary arts. These advertising-free forums are provided free of charge through donations from Society members. Anyone may read the forums, but to post you must create a free account.

Why did the sugars in my rum crystallize and fall out?


cteavin
 Share

Recommended Posts

Hi,

This summer I made a huge batch of candied pineapple ending with 70% sugar saturation. I had a bit more than I needed, so I brought the last container down to 80% saturation. After a few days in the container the batch at 80% crystallised. I remelted it twice, but always, after a few days, it crystallised.

I dislike wasting. I put the crystallised syrup and pineapples into a 4 litter container and poured 2 litres of Myer's Rum over it. To help it dissolve I closed the container and put it in a hot water bath for an hour. The next day I tasted it and it was perfect.

A week later, today, I opened up the cupboard where that batch of pineapple rum is stored and all of the crystals fell out of the rum in a thick layer on the bottom with the pineapple on top. The rum tastes of pineapple, but it's no longer sweet. What happened? I'm curious about the science of what's gone on. I'd also like to know if there's a way to permanently keep it in suspension without adding water. Any suggestions on what to do with it (filter it, remelt it before serving, etc)?

Thanks,

Link to comment
Share on other sites

Sugar precipitated because the solution was supersaturated: more sugar was dissolved in the liquid at a heated temp than can remain in solution at room temp. The pineapple may have encouraged nucleation, as it changes the pH of the sugar syrup.

Invert sugar (mix of glucose & fructose) is typically used to reduce crystallization.

Link to comment
Share on other sites

80% shouldn't be enough for it to be considered supersaturated (for sugar, that is). But there's still a heck of a lot of sugar sitting in solution and it wouldn't take much to cause it to start precipitating out.

Link to comment
Share on other sites

I think I messed up my thought process for the calculation, 200g sucrose + 100g water is about 66% which is close enough to your number that I'm happy to say I was incorrect ;)

unless I'm completely misremembering those numbers from chemistry, many years ago!

Link to comment
Share on other sites

 Share

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...