What is corn syrup?
Corn syrup is a mildly sweet, concentrated solution of dextrose and other sugars derived from corn starch. It is naturally sweet. Corn syrup contains between 15% to 20% dextrose (glucose) and a mixture of various other types of sugar.
I don't know how you'd decide how much to prime since you couldn't do it 1:1 by weight. I don't think I'd try it, but maybe others have.
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Most corn syrup you get at the supermarket, like Karo, had vanilla flavoring. Besides that, I'm not sure if there's consistiency in the syrup from batch to batch or brand to brand, making measuring for priming difficult.