It is quite a knack to properly pack butter in large packages, and
the work needs to be carefully done. Some use it too violently, by
pounding it down, and thus making the butter greasy or oily. It should
be gently pressed together in the package in such a way as to leave
no spaces filled with air, for the air will surely mingle with the
surrounding butter and injure its flavor. A good way is to begin the
pressure at the center and work carefully toward the circumference, so
that all air may escape at the sides. In this way, perfect solidity of
the mass is secured, and it is left in the best condition for keeping,
so far as the packing is concerned.