The acid smell very often found in casks may be attributed to absorption in the pores of the wood of acetic and lactic acids - a very small quantity of either of them having power to communicate their principle tootny fermenting liquid with which they may be brought in contact, and increasing very fast at the expense of the alcohol in the liquid, while at the same time causing unsoundness to a greater or less extent, according as the temperature of the atmosphere may be high or low. Bearing this in mind, it is of the utmost importance that all free acid which the cask may contain should be carefully neutralized before filling with a liquid so liable to change as fermenting wort. Casks before filling, after being well washed with boiling water, should be allowed to cool, and then examined by some responsible person as to their cleanliness, acidity, and probable musti-ness; the cask is well smelt, and usually a light is passed through the tap-hole, so that the examiner may view the interior. Any cask that may smell sour (especially in summer weather, or when required for stock or pale ales) should be rejected, and be well treated with lime.

This should be put into the casks dry, small lumps of the lime being broken, so that they can be easily in-serted in the bung-holes, and when sufficient has been put in (say, about 4 lb to a barrel), then about 4 gal. of boiling water must be added, the casks bunged up , and kept so for a few hours, occasionrnly rolling about. The lime should then be well washed out, and the casks steamed, and allowed to cool, whan they will be in a fit condition for containing the most delicate liquid without any injury. The hard brown substance, which on being scraped with a nail leaves a white mark, so often found in casks, is a deposit that forms from the constituents of the liquid contained in them, and is often carbonate of lime, or yeast dried, or both. When this is formed, the only effectual method of cleansing is to take out the head, and put it into the cooper's hands to be well scraped, until every particle of the fur is removed. Cask-washing machines never remove fur or thick dry deposit properly; they are very convenient in a general way for the usual run of casks, but any exceptionally bad must be unheaded, and cleaned by hand.

For stock ales it is a good plan to rinse with solution of bisulphite of lime just before filling trade casks. (2) With regard to the coating spoken of in (1), it not only preserves the wood but keeps it clean and sweet, and does no harm at all to the beer. It takes some considerable time before the wood is coated with such a protecting enamel. It occurs alike in rounds, puncheons, and stone squares. Formerly it was customary to have all vessels that were furred over thoroughly dressed by the cooper, but now intelligent coopers advise brewers to keep it on. (3) Blow sulphur fumes into foul casks by fumigating bellows, such as gardeners use when fumigating conservatories. The sulphurous acid formed by burning brimstone is a powerful purifier, and will not leave an unpleasant taste, being easily washed away. (4) Cider casks. - Half fill each cask with boiling water, and add 1/4 lb. of pearlash, then bung it up, and turn over occasionally for 2 days, then empty, and wash with boiling water. (5) Scald out with boiling water; if the heads are out, put them over a straw fire for a few minutes, so as to slightly char the inside.

If you have a steam boiler, partinlly fill with water, and admit steam through the bung-hole by a pipe down into the water,;ind so boil. (6) Vinegar casks. - Old vinegar barrels become impregnated 2 to such an extent with acetous substances that it is next to impossible to render them fit for the storage of any other liquid. Fill the barrels with milk of lime, and let this remain in them for several months, then rinse out well with plenty of warm water, and steam them inside for 1/2 hour.