Cheese sauce failure

[IzzyGee]

Normally I make acceptable cheese sauce. I have made cauliflower/broccoli gratin and the sauce has split into curds and watery stuff. Is this because I inexplicably bought low fat cheddar or because the oven was roasting? (I am staying not in my own house at the moment and it has an aga.)

Did you par cook the veg first? If so, it may have not been sufficiently drained.

Is this because I inexplicably bought low fat cheddar
Possibly? Don't use low fat anything when making cheese sauce... it won't work as well.

I think the hot oven could have caused it. If you boil it once the cheese is in it will curdle.
But also cauliflower can be watery (despite thorough draining) - not sure why sometimes this is a problem and other times not.

Low fat cheddar, I’ve found this in the past. I believe it’s because of the lack of fat but could be wrong. I did rescue mine when I did make this mistake by sieving it and mixing lots.

Cauliflower also breaks up and releases water in a very hot oven. So could be both!

It's the low fat cheese. Ick

It's the low fat cheese. I once tried using low fat cheese, low fat spread and skimmed milk, it wasn't pleasant!