Is it possible to prepare a (large) batch of roux and then freeze it, or will the texture and flavour be destroyed in the process?
You can freeze roux and store it up to 6 months without any problems. I put them in plastic ice-tray forms until they are frozen, then move them to a refrigerator bag.
Just keep following things in mind:
- Leave a bit of room in the container before putting it in the freezer - roux expands when freezing.
- Bring it to room temperature before using it.
**RE: "although why you would want to is another matter" and "It's very simple to make fresh .. wouldn't it take as much time to defrost as it would take to make it in the first place?"**** That's because if you are making a white roux, it's quick and easy, but even then I freeze good chicken roux (white) to use later for gravies and sauces. That kind goes into ice cube trays, then into bags. Works fabulously, especially good for singles small families. But the main reason for freezing a roux for gumbo and other dishes calling for a darker roux, is that it takes a lot of time and it uses up a lot of natural resources to make it. Where I live both gas and electric are pricey, so making 1 big batch and keeping it on hand makes sense. Getting it to a peanut butter color takes about 1 hour cooking time, slow and steady, longer for a dark (mahogany colored) roux. So I make mine to color, add the trinity and liquid. I use what I need for "this" dish, let the rest cool down and package the rest in recipe sized portions in bags that I can lay flat in freezer for space saving. When I want a gumbo on what is going to be a "no time to cook" day, one of those goes into the crockpot with the main meat (never the sausage yet) and more liquid and off I go to do ... the rest of life. Freezing it lets me enjoy it more often.
It's very simple to make fresh .. wouldn't it take as much time to defrost as it would take to make it in the first place?
If you want to thicken a sauce which is already liquid - mix flour and butter into a paste and add a spoonful. Because the butter melts gradually, it disperses the flour without leaving lumps.