Sugar Syrup Stages at High Altitudes

[Panaderia Canadiense]

Here's a question for you confection gurus. I'm aware that at high altitudes, the temperature at which water boils is reduced (for example, at 3,000 meters, where I live, water boils at 89.8 C.)

Does sugar behave the same way: to wit, do I have to calculate a much lower temperature than I'm used to for firm-ball syrup? If so, do I use the same ratios I'd use to compute water boiling time to figure out what my new temperature is?

I ask because my syrups have been cracking out well below the temperatures I'm used to using, but if I'm overshooting by tens of degrees I wouldn't be surprised by that.... Otherwise, I'm not sure what's causing it - my instruments are all spotless and without the kind of flaws that would normally cause this kind of behaviour, and neither the sugar I use (98% sucrose from the San Carlos mills in Guayas) nor the water (distilled) has changed.

Thanks in advance.

(edited to fix a non-sequitur)

Edited March 9, 2013 by Panaderia Canadiense (log)

[Chocolot]

Yes, you need to adjust. Test your thermometer in boiling water. What ever it reads, subtract it from your recipe. Example: I am at 5000 feet. Water boils at 202 on my thermometer. I subtract 10 degrees from recipes written for sea level. Usually, the adjustment is 1 degree for each 500 feet in altitude.

Edited March 9, 2013 by Chocolot (log)

[Darienne]

Yes for candy recipes. I make toffees and lollipops in Utah (4000 ft where I am) and if I am using a thermometer test, then I calculate downwards in a simple fashion...no percentages...just subtract a straight number of degrees.

[Panaderia Canadiense]

Thanks. I'll adjust accordingly, then, and see if it works better for me.