You don't technically NEED the cornstarch in there....if you just add the sugar verrrry slowly and you don't overbake the pavlovas, you'll get the same effect. The shelf life will be diminished, but if you make day-of, you should be happy with the result.
When substituting starches in recipes, think of what you're trying to accomplish and that will help you with a substitute. You're not thickening anything here so other "thickeners" might not be suitable, but pretty much any other plant starch should work here. I would just choose something that doesn't have a bold flavor. Potato starch would be my suggestion.
This is the first thing that popped up when I googled your question. http://www.myrecipes.com/how-to/cooking-questions/constarch-substitutes
With a corn allergic partner you might want to develop a list of alternatives for corn in all its forms.
Good luck.
3 Comments
When substituting starches in recipes, think of what you're trying to accomplish and that will help you with a substitute. You're not thickening anything here so other "thickeners" might not be suitable, but pretty much any other plant starch should work here. I would just choose something that doesn't have a bold flavor. Potato starch would be my suggestion.
With a corn allergic partner you might want to develop a list of alternatives for corn in all its forms.
Good luck.