While a classic velouté contains approximately 3tablespoons (20grams) flour per quart (liter), giving it a distinct floury quality, a modern velouté is made with less roux or no roux at all. Instead, modern thickeners give the sauce a more subtle quality without contributing a strong flavor.
Reduce the stock by one-third, until 1quart (1liter) remains. Keep the saucepan to one side of the burner and skim off froth and scum. Blend the Ultra-Sperse 3 and lambda carrageenan into the stock with an immersion blender. For a thicker sauce, add more Ultra-Sperse 3, a little at a time. Bring to a simmer. Strain through a fine chinois.