White sauce

[Jux]

What happens if you let the milk boil when making white sauce? Will it fail to thicken?

Just curious.

I just made some white sauce for cauliflower cheese this afternoon. The whole time I just kept whisking, it was bubbling at the end for a couple of minutes.

I put the milk, flour and butter all in together at the beginning.

by the time it gets to boiling it should be thick.

I get it to boiling point, and turn it right down and then bubble gently for 5 mins to cook the flour

I am making cheese sauce for cauliflower cheese too!

I was just curious about why so many recipes say so sternly that you shouldn't allow the milk to boil. I'm just a bit bored with stirring.

yes I put it all in at the start too

What method are you using? I cook out the flour and butter, add milk, and bring to the boil.

If it's just the milk, you get a skin on the top if it boils, I think.

It warns you not to let the milk boil, because there's a risk of it either boilng over (milk can do that really suddenly) or catching and burning, so your lovely white sauce ends up speckled with nasty brown bits.

Do you bring the milk to the boil first before adding it bit by bit to the roux? (I never bother, i either add it cold or bring milk, butter and flour to the boil while whisking all the time, as per Delia.) But i thought you had to cook the sauce at lesst at a simmer for a little while once it has thickened, thogh, to get rid of the 'raw' flour taste, don"t you?

I make the sauce in the way my grandmother taught me, which is how my mum made it, and etc etc etc ; make a roux, add milk slowly whisking/stirring, very low heat, keep adding milk until you stop. That's the basic.

On this occasion, I melted butter, softened chopped onions in it, added flour until I couldn't add any more, added mustard powder, tiny bit of mace likewise of cayenne. Then I started adding milk. Lots and lots of stirring later I had a thick onion sauce and chucked in a load of cheese, stir stir stir until melted. End.

It's OK, my sauce is fine, the milk didn't boil, it's a lovely thick cheesy sauce for cauliflower and we shall pig out tonight.

I just wondered if there was some reason you shouldn't let the sauce boil, like it would split or something? Something, like the flour behaves differently... curiosity will kill me one day. I expect I'm a cat.