Mrs. Beeton, The Book of Household Management
“ All pans, jugs, and vessels intended for milk, should be kept beautifully clean, and well scalded before the milk is put in, as any negligence in this respect may cause large quantities of it to be spoiled; and milk should never be kept in vessels of zinc or copper. Milk may be preserved good in hot weather, for a few hours, by placing the jug which contains it in ice, or very cold water; or a pinch of bicarbonate of soda may be introduced into the liquid. MILK, when of good quality, is of an opaque white colour: the cream always comes to the top; the well-known milky odour is strong ”
