I've recently started to experiment with making hard candy from straight corn syrup rather than conventional sugar, and so far it has worked remarkably well. Aside from increased sweetness and improved mouthfeel in the final product, the process is faster and more reliable — there is no need to wait for sugar granules to dissolve, and the corn syrup boils nearly uniformly from start to finish without any need to adjust the heat or any risk of going out of control. It's been consistent enough that I'm comfortable leaving the pot entirely unattended on a timer until nearly the final minute and doing other tasks while waiting for the syrup to come up to temperature.
However, hard candy recipes produced in this way seem to end up slightly softer than they do when making them with traditional sugar, and it's really not clear to me why this is — if this is due to the corn syrup requiring a higher temperature to reach the same moisture level; if fructose sugar glass just softer generally even at the same hydration, or something else.
For hard candy at least, I've considered trying to add back in some amount of regular sugar again to try to be able to make harder sugar glass, but I have especially for more specific candy types like nougat (that are sensitive to viscosity/hydration) it really isn't clear to me how to compensate for this difference.
Unfortunately despite searching I have yet to find even a shred of information on the subject of making candy using corn syrup in this way; all of the google search results are polluted with sources that do little else but spout the evils of corn syrup and decry the very concept of using anything but the One True Saccharide for candy-making, and with "fructose free" candy recipes that straight-up walk you through the process of hydrolyzing part of the sugar to make the fructose yourself, without bothering to mention that fact.
Does anyone have any sources or know where I can find actual information on how to use corn syrup for candy-making, and how to compensate when making a substitution for regular sugar? In a perfect world I'd love if I could find a reference source with information on how to derive (or even just tables listing) the temperature/hydration and hardness curves for different sugar mixtures, but even just basic information and recipes would be great.
The particular syrup I'm using here is Golden Barrel High Fructose 55 (although my question isn't limited to just this syrup in particular). Here's the description from the datasheet:
High Fructose Corn Syrup 55 is a second generation high fructose syrup. The principle sugars, fructose and dextrose, give it a sweetness comparable in most foods and beverages to sucrose or invert sugar. The high sweetness level of high fructose corn syrup 55 provides desirable characteristics to carbonated drinks, still drinks, and processed foods.
Also, here's my best sugar glass recipe at this point, for reference:
Dispense 1 lb of HFCS55 into a pot. Place the pot on the stove on high and set a timer for 14 minutes. Return once the timer goes off and continue to heat for about another minute, until temperature reaches 310 F. Remove from heat and wait for it to cool below safe temperature for additives. Stir in color and flavor, and process into desired shape.