Making a big batch of roux is a hassle, so I'm investigating how to make my life a bit easier.
According to 'Ideas in food', you can make roux in a jar in a pressure cooker. Nice, but the quantity is too little for my needs.
In the Cajun cuisine you can make roux for gumbo in the oven. That won't work for me as I need it to work as a thickening agent. Maybe it would work at a lower temperature.
The problem is to lose the raw flour taste. I'm thinking of mixing the butter-flour as always, on the stove-top. Then transfer the batter to a sous vide bag and let it bathe for 12 h at 85ºC (at which point the starches should be gelatinized).
What do you think? Is 12h too long or too short? Is 85ºC high enough to lose the raw flavour?