Sachertorte glaze help

[Zachary]

My wife wanted a Sachertorte for her birthday, so I dusted off my copy of Rick Rodgers "Kaffehaus", and made the regular Sachertorte recipe, very straight - no variations, no weird additions. I made the glaze (1.5 c sugar, 3/4 c. water, 6 oz Godiva 72%), cooked it to 231 degrees (we're at 1700 feet here, and water boils at 209 - the recipe called for 234). Stirred for a minute to let the glaze cool and thicken. I poured the glaze over the cooled, filled cake, and let that cool, put it in a cake dome, and served it about 24 hours later.

Here's the weird thing. When I served the cake, the glaze (which tasted exactly like a melted Tootsie Roll when warm) was very thin, and was tacky in places and dried to a sugary "shell" in others. There were no obvious sources of moisture in the cake layers, and it's very dry here right now.

From this, can anyone diagnose what happened? Why partial crystallization of the glaze? Would a tablespoon of corn syrup have solved this problem?

Thanks,

Zachary

[GaryK]

You may have not heated the sugar high enough. Sugar decomposes as it is heated into over 100 different compounds. Underheating it likely left it decomposed less than needed to achieve the desired effect. High altitude has nothing to do with this process. You can see this effect in the difference of structure in heating sugar to 240F (soft ball) and 255F (hard ball).

[Zachary]

Gary,

Should I not have reduced the final temperature of the glaze by 3 degrees? I figured I needed to get it to 22 degrees above boiling, which for me would be 231.

Thanks,

Zachary

[GaryK]

You were thinking in terms of water, but you were dealing with sugar. Sugar behaves differently depending on how hot it gets. That is seen in the various stages of sugar heating e.g. soft ball, hard crack, etc. It makes no sense to lower temperatures since you were trying to break sugar down by heat.