Can I make corn syrup?
Corn syrup is made commercially by acid treatment of cornstarch. It is mostly dextrose (glucose). I have corn sugar, however. If I make a syrup of that wouldn't it be the same thing?
My reason for this is that Karo light corn syrup has high fructose corn syrup mixed in to make it more sweet, and Karo and organic corn syrups have a bit of vanilla in them (why?). I just want the pure product.
You can buy pure glucose.
Having driven past corn refining plants many times in Iowa, Illinois and Missouri I don't think you'd be happy trying to recreate this product at home. The enzymatic reactors STINK.
By adding cream of tartar (acid) to sugar syrup, you're doing a "poor man's version" of what Lyle's does when they make their Golden Syrup. Lyle's started out as a byproduct of the refining process, like Steen's in the US, only lighter to British tastes. From their website: "Sugar syrup is acidified so that the sucrose inverts. Quite simply, the sucrose sugar molecule splits in half to give glucose and fructose sugars. This inverted syrup is blended back with the original syrup to give a partially inverted syrup."
The inverted sugar is what keeps it from crystallizing.
Here's how http://www.cooks.com/rec/view/0,1823,...
This corn syrup substitute is just sugar syrup with a bit of cream of tartar (acid) and salt. This makes the same amount as a bottle of Karo, with the bonus of no vanilla flavoring. Cheaper too.
I can't figure out why the vanilla is in Karo, and their website says that it always has been. No excuse as far as I'm concerned.
Sometimes when I make caramel for flan or a similar recipe that uses only a small amount of corn syrup to prevent crystallization, I add a dash of cream of tartar if it's closer than the corn syrup and it seems to work just as well. Lazy me.