Someone asked me this question today, and I'm not sure if there's an answer: She asked why it is that sometimes cooked spinach leaves a dry-ish feeling on your teeth (kind of tannic), and other times it doesn't? Is there a chemical in the spinach that makes it that way? She aslo asked what she can add to reduce that sensation. My answer was to probably add fat, which would make it slippery, and hence less detectably dry. Any other insight?