It causes complexation of proteins (including fining protein like gelatine, isinglass, etc.) and precipitates quickly forming compact fining deposit. The flocculation of fining is formed when negative charged silica sol particles react with positive charged protein particles. The polyphenol content has no special impact for flocculation.
KlarSol Speedfloc Technical Data Sheet
KlarSol Speedfloc Specification
KlarSol Speedfloc Safety Data Sheet