[Daniel García]

I was watching this veal stock (or demi-glace) video on YouTube and the guy said eagerly that the stock shouldn't be boiling but instead just simmered.

Why is this? Is there any particular reason?

Thank you all for your attention.

 

[cheflayne]

Boiling makes a stock cloudy because it lends itself to emulsifying the fat and soluble proteins.

 

[Daniel García]

Boiling makes a stock cloudy because it lends itself to emulsifying the fat and soluble proteins.

That actually makes sense, thank you so much, now I will never boil my stock again!

 

[mike9]

I learned that from watching "Tampopo" many moons ago.

 

[chrislehrer]

Note that it's a question of motion, not heat. A pressure cooker makes great stock, because you've got lots of heat for flavor extraction, but the liquid doesn't roll.