Why do recipes call for cornstarch?

A student’s mother recently gave me a Chinese cookbook for “beginners” after catching wind I don’t and can’t cook. The English is great and I finally got a chance to thumb through it last night.
What caught my attention was that most of the recipes required cornstarch…

Is it unhealthy? I’m glad it’s not oil… but i don’t really like that cornsyrupy texture to the liquid in my food. Do you think it can easily be omitted without ruining the whole dish? I haven’t gotten around to trying anything yet… but when I do, I don’t want to have to buy cornstarch.

makes the sauce thicker so it sticks to the food rather than staying as a thin soup. if you leave it out your taiwanese friends will be happy (as they seem to like runny soups etc) , your hong kong friends will be upset as they prefer stickier sauces.

up to you. it’s not particularly unhealthy.

I agree. Shouldn’t hurt. One doesn’t use very much I don’t think and it is commonly used for thickening sauces, as noted. And as far as I know its a pretty common, ordinary, natural ingredient.

bon apetit

If you do have to thicken, it seems there would be other ways to do it without cornstarch - flour has starch in it too, so it can thicken things the same way without buying an extra ingredient.

Uhm, you use different kinds of flour depending on the sauce you make.
Plain flour doesn’t give a clear sauce as corn or potato starch does.
Corn startch is better if you need to cook the dish after you’ve added the starch as potato starch can only be brought to the boil and then whatever you cook have to be removed from the heat or it won’t stay thick.
You can also use arrowroot instead of corn startch, supposedly it’s better for dishes with high acid content as corn starch doesn’t work well with acidity. It does produce a sligtly stickier and stringier sauce though, but it’s less calories if you care about that sort of thing.
You only use about a table spoon of flour for a sauce that should be enough for four servings. I’d stick to using plain flour if you make a milk or cream based sauce, as corn starch makes those kind of sauces a bit to “thin” the whole texture of the sauce is very different, but I guess that’s more for classic Swedish sauces or a bechamel than Chinese style cooking.