One of those mysteries (to me at least) in Chinese food is the use of starch as an ingredient. It always bugged me a little…I mean…why? The answer, on hindsight is remarkably simple, but let’s indulge me a bit here.
Is it just to make things look shiny and palatable? Or is there something more to it? I have seen it on cooking shows. I have seen it in books. And it is one of the major complaints of commercial Chinese food…too much corn starch. However it is supposed to be such a basic know-how that no one writes about the “why”. Infuriating!
Let’s try to work out the answer. On the properties of starch, I know that it increases the viscosity of the medium it is in, in other words, thickens the sauce. I also know from my childhood school projects that dissolved starch can also be used as a glue. So it is thick and sticky…
I didn’t quite make the connection until I started cooking vegetables one fine day (and quite a long time after I started cooking…). Vegetables have a habit of ejecting a lot of water when stir fried, diluting whatever flavorings I add. I asked myself how I would solve this problem when it just suddenly struck me…Corn starch.
How so? Simple…I needed the flavorings to stick to the vegetables so as to retain them. Turn the ejected water into glue and it will do what I need…
So yes, to reiterate, the corn starch thickens the water ejected from the vegetables and makes the resulting sauce stick to the vegetables, allowing the taste to be retained.
“Now I get it!”