Yesterday I was idly watching Martha Stewart baking. I forget exactly what she was baking (it was, as usual, incredibly complicated) at one point she added to chopped apples a combo of flour and sugar.
I always wonder why not just use confectioner’s sugar, which is sugar and cornstarch? Would that not be easier?
Well, one reason could be that cornstarch has bit of a different texture and mouthfeel than flour when cooked. Also, I’m not sure what the proportion of sugar to corn flour is, maybe to get the amount of thickening needed it would be too sweet?
I believe only about 3% cornstarch is added - enough to keep it from clumping but not enough to act as thickener.
Also, cornstarch is quicker to break down again with prolonged heating, which could become an issue with something like a pie…
But it is an excellent point to remember when using confectioner’s sugar!!! It isn’t JUST sugar, so depending on the application you may want to use super-fine sugar - which has no corn starch or maybe you want/could benefit from the little corn starch.
Which is why I use tapioca starch for fruit desserts, as it is heat stable, doesnt go gummy like flour, and leaves a beautiful clear glaze on the fruit. It also doesn’t take as much tapioca starch as flour, so odd flavors and textures are less likely.I
