I'm afraid I can't answer that one as I dont normally use cereal to thicken my LOs milk - I use an already thickened formula - Omneo Comfort. The other day I hadn't got any of my norma formula so as an emergency I used a thin formula and thickened it with a teaspoon of cereal in a 9oz bottle - but that was just a guess!
Hope someone who knows more can help.
H xxx