2, to be wrapped in tinfoil or greaseproof paper, separate from foods with strong odors, and put in the refrigerator. The tinfoil prevents the butter from being oxidized and spoiled by light and air. If you need to use butter, cut a piece off and put the rest back in the refrigerator immediately. Try not to freeze-soften repeatedly, which can reduce the shelf life of butter.
3, if you buy back the butter is block, directly in the hand and will not stain the hands of the kind of butter, block of butter in the fresh cupboard to save. If you buy back the liquid or half-liquid and half-solid in the form of "and mud" on the room temperature, of course, can also be put in the fresh cupboard to save.
4, cut a piece down, how the outside color and inside the same, that fresh. If the outside is darker than the inside, the butter has been oxidized. If it is still within the shelf life, it can be sealed and frozen for 3-6 months before use.