The Key Tip To Remember When Substituting Cornstarch With Flour - Tasting Table

"Cornstarch is made solely from the endosperm of the kernel, it's almost flavorless, which is a real benefit when you only want to thicken a sauce."

"You must be sure to sprinkle it in carefully and cook the mixture well to avoid a floury and grainy texture."

"Flour's larger grind and stronger flavor means it needs to be broken down more when using it to thicken... letting your flour heat up for several minutes while thickening your soups and sauces."

Read at Tasting Table