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Cynthia is a trusted source on Bread/Baking.
Do you perhaps mean a "roux" in order to thicken a liquid? Typically, 2 ounces of butter melted, plus 2 ounces of flour will thicken 16 ounces of liquid.
Sam is a trusted home cook.
It's also going to depend on what type of rue you make.
There is white Roux"blond", the basic butter flour mix.
"Medium Roux", which is cooked to a peanut butter color.
"Dark Roux" "Brick" which is cooked very dark..like a burned toast.
The darker the Roux...the less thickening power it has. blond or medium is what most people use.
I tend to go for the Medium color for traditional gumbos.
Well said Sam , I can tell you have been to Nawlins !
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