I want my buttercream to be nice and spreadable but still crust nicely so I can smooth it. Will adding karo syrup or water to it make it lose it's ability to crust??
I've added more milk to my recipe and it makes it thinner for easy spreading or piping, but it still crusts fine ... because the fat/sugar ratio remained the same.
For a shortening (or butter) and powdered sugar type of buttercream, adding water/corn syrup will thin the icing but prevent crusting. In fact, Wilton used to say to add corn syrup to thick icing to make it spreadable/smoothable.
Unless you get the icing too thin I can't see how adding liquid will make it not crust.
Crusting is based on the sugar to fat ratio, not the liquid amount.
i tried a new recipe and it called for karo syrup and i followed the directions, and it came out awful, it was sticky, and nothing i could do would help it, the only time i use karo syrup is when i do my butter cream roses, just a bit, i found out this good hint on here, but i wouldn't use karo syrup to thin your bc i also use a little water.