A skin had formed on the top of the milk.

奶上结了一层奶皮。

《牛津词典》

A skin has formed on the milk.

牛奶上面结了一层皮。

《新英汉大辞典》

Ingredients to embrace: Veg, fruit, extra-virgin olive oil, rapeseed oil, fish (especially oily), lean meat such as rabbit and chicken (no skin), skimmed milk, oats, wholemeal bread, brown rice.

放手去用的食材：蔬菜，水果，初榨橄榄油，菜籽油，鱼(特别是含油的)，瘦肉(如兔肉和去皮的鸡肉)，脱脂奶，燕麦，全麦面包，糙米。

youdao

They carry goods and people, and they provide products including milk, skin, hair and bone.

VOA: special.2009.01.13

Milk really does condition skin.

FORBES: Getting Milked

Many of the faithful carry offerings of milk in paal kudam (milk pots) often connected to their skin by hooks.

BBC: Malaysia's Thaipusam festival

But milk is being hyped as a key ingredient in some new fast-selling skin and bath products from Caswell-Massey, Avon, Almay and other companies.

FORBES: Getting Milked