Now that it's simmered long enough, we're asked to skim the scum off the surface of the stock, which I presume you might have more of if you actually have bones in your broth.

现在它已经煮得足够长了， 我们被要求撇去汤表面的浮渣，我想如果你的肉汤里真的有骨头的话， 你可能会得到更多的浮渣。