_Cleaning Casks._--(1) 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 to any 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 neutralised 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 mustiness; 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 inserted 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, occasionally rolling about. The lime should then be well washed out, and the casks steamed, and allowed to cool, when 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