Gluten free vegan roux

[rebgold]

I'm having trouble with a sauce at my restaurant, a mushroom "veloute" thickened with a gluten free flour mix/olive oil roux. It starts out fine, but thins out as it sits in the steam well. I don't know if it's a combination of steam from the lid dripping in water, the gluten free flour losing it's thickening power as it's held at 140, or something to do with the olive oil?

[Lisa Shock]

It's the gluten-free flour. Flour is used in roux for its resilience. Substitutes aren't going to work the same way -most gluten-free flour is designed to work in pancakes or biscuits, not as a thickener. A lot of these are rice four, potato flour, or sorghum with various gums and maybe gelatin, and those starches and additives don't have the properties of wheat flour. You might try arrowroot. It's not the same, but, it holds up to hot holding and reheating.

[Mjx]

I've had fairly good results with straight rice flour/starch (whichever I have on hand), and sauces and such made with these seem to handle extended heat and reheating very well (even when I've flaked, and forgotten it for several minutes, and left it seething away). The dripping shouldn't be problem, but you could put a cloth under the lid to absorb the condensation, to see whether it makes a difference.