In making fondant it may help to understand a little of the chemistry behind the ‘recipe’ By sub-critically heating the sugar (sucrose) we are attempting to split the sucrose back to the building blocks from which it is derived - glucose and fructose (this can be achieved at as low a temperature as 60’C). The product of temperature degradation of sucrose is also known as invert sugar; we are also attempting to bind a proportion of water (at a non-molecular level) to make this available to the bees as well. If you go too high with regard temperature you move beyond a saccharide split to denaturation of the sugars and quickly through to what would be recognised as 'caramels and toffee', also driving off any remaining water. Typically a little additional glucose is added to disrupt the fructose crystalinity and keep things soft and pliable. Glycerol is mentioned previously in the thread, This is a polyol rather than a sugar and so is not immediately available to bees as a nutrient, whilst it will soften a fondant it also disrupts hydrogen bonding and so destablises the fondant in the medium term - so best to stick to glucose as your ‘softening agent’. The critical thing in fondant manufacture is temperature, but supported by time, not boiling so fast that you go too high and not boiling so slowly that you drive off all moisture. Temperature rise rate increases disproportionately as the water content falls so it's easy to over-cook your batch. I hope that helps. R