When butter is to be sold on the spot, or in the neigh bouring markets, it is divided into rolls of a pound, or half a pound ; or into lumps of 24 ounces, called dishes in some parts of England ; but when it is to be kept, or carried to a distance, quantities of 84, 56, or 28 pounds, are put up together in casks, usually called tubs, firkins, and half firkins.
When the butter has been sufficiently impregnated with the salt, by being spread out in thin layers, sprinkled with it, and thoroughly wrought, it is then to be gently pressed into the tub or firkin, which must not, however, be filled quite up, but room left at. top to receive a layer of salt, half an inch or an inch in thickness. in seven or eight days, the salted butter detaches itself from the sides of the firkin, shrinks, and occasions interstices. These, if allowed to remain, would injure the butter. by 7 admitting the contact of the air. They are, therefore, to be filled up by a saturated solution of salt in water, or brine strong enough to carry an egg. The butter is then to be covered by a new layer of salt, and the head of the vessel put on.
Before the butter is put into the firkin, care must be taken that the latter be well seasoned : and this is effect ed by exposing it for two or three weeks to the air, and frequent washing. The readiest method, however, is by the use of unslaked lime, or a large quantity of salt and water well boiled, with which it should be scrubbed se veral times, and afterwards thrown into cold water, to remain three or four days till wanted. It should then be scrubbed as before, and well rinsed with cold water ; and before receiving the butter, every part of the inside of the firkin must be carefully rubbed with salt. Indeed, the surest of all methods to preserve butter from spoiling, after it has been properly salted, is to keep it constantly immersed in a saturated solution of this substance. A friend of the writer of this article informs him, that he has preserved butter in this manner at sea for a very long period. It might deserve attention, to try to discover a species of wood that would not communicate any taste to the butter. • An excellent composition for preserving butter may be prepared, by mixing one part of saltpetre, one of com mon salt, and two of sugar. This thoroughly wrought
into the butter, will keep it sweet for a very long time, and communicates to it no salt or disagreeable taste.
When butter is to be exposed to the heat of a warm climate, it should be purified by melting, before it is salted and packed up. Let it be put into a proper ves sel, and this into another containing water ; let the water be gradually heated till the butter be thoroughly melted ; let it continue intlfis state for some time, and the impure parts will subside, leaving at the top a perfectly pure transparent oil. This, when it cools, will become opake, mud assume a colour nearly resembling the original butter ; being only a little paler, and of a firmer consist & nee.
This refined butter must be separated from the dregs, salted, and put up in the same way with other butter ; and it will keep much longer sweet in hot climates, as it retains the salt better. It may also be preserved sweet, without salt, by adding to it a certain proportion of fine honey, and mixing them thoroughly, so that they may be perfectly incorporated. A mixture of this sort has a sweet pleasant taste, and will keep for years without be coming rancid. It might of course be very useful in long voyages. Dr Anderson thinks an ounce of honey sufficient to preserve a pound of butter.
To preserve butter for a long time fresh without any foreign mixture, the best method perhaps is, first of all to wash butter-milk completely out, and then to keep the butter under pure cool water, frequently renewed. Some wrap it up in a wet linen cloth, to defend it from the influence of me air. But though fresh butter be kept cod and from tl)e air, it will in no very long time be come rancid. We cannot by any means keep it fresh from one year to anot! Cr, or transport it to a distance in •00(1 ccmdhion. ltaricid butter, to 1110st people, is ex tremely disagreeable. A very small quantity of it will be ohs& rred by Mau} in a large mass of meat, that it may have been employed to season. Few stomachs can digest rancid butter. Some are so delicate, that the use even of fresh butter, of milk, of cream, and in general of all oleaginous substances, affect them with difficult and painful digestion.