A great enemy of the Victorian brewery (and the modern brewery that brews with wooden barrels!) was soured barrels. Barrels that are not thoroughly cleaned and sterilized between brews can become infected with microbes which will lead to stinky skunky beer! This was an ongoing issue in brewhouses and I came across a discussion of methods of ‘sweenting stinking or musty casks” in MacKenzie’s Five Thousand Receipts which was published in Philadelphia in 1851. Google books has a copy from 1853 available online here. The author, Colin MacKenzie has the following options available for those interested in cleaning out their skunky beer barrels
To sweeten stinking or musty casks. Make a strong lye of ash, beech, or other hard wood-ashes, and pour it, boiling hot, into the bunghole, repeating it as often as there is occasion.
Or, fill the cask with boiling water, and then put into it some pieces of unslaked stone-lime, keeping up the ebullation for half an hour. Then bung it down, and let it remain until almost cold, when turn it out.
Or, mix bay-salt with boiling water, and pour it into the cask, which bung down, and leave it to soak.
Or, if the copper be provided with a dome, and a steam pipe from its top, pass the steam into the casks.
Or, unhead the cask, scrub it out, head it again; put some powdered charcoal into the bung-hole, and two quarts of a mixture of oil of vitriol and cold water. Then bung it tight, and roll and turn the cask for some time. Afterwards wash it well, and drain it dry.
Or, take out the head, and brush the inside with oil of vitriol, afterwards wash it, then burn a slip of brown paper steeped in brimstone within the bung-hole, and stop it close for two hours, when it should be well washed with hot water.
For those unfamiliar with 19th century terminology, oil of vitriol is sulfuric acid, bay-salt is sea salt, unslaked stone lime is the caustic quicklime of today and brimstone is an alternative name for sulfur. Not particularly nice stuff to be working with. He does mention one method of sterilization that may be considered ‘organic’ though perhaps rather unsavoury!
Collect fresh cow dung and dilute it with water, in which four pounds of salt and one of common alum are dissolved. Let these be boiled together, and poured hot into the barrel, which must then be bunged and well shaken. This operation should be performed several times, taking care to rinse the cask out every time, with clean water.
I can see Mrs. MacKenzie telling Colin in no uncertain terms, that he had better find a different pot to boil his cow dung disinfectant in, because it wasn’t going in her pudding pot! I suspect that particular recipe might also impart some interesting flavours into beers brewed in that barrel. By the mid 1860s many breweries were beginning to convert to steam power and with it came the added bonus of high-temperature steam available to disinfect barrels with high pressure boiling water between brews.
So next time you have a sip of beer, give a silent hurrah for steam power and be glad that Colin’s recipe for cow poo sanitizer never became the industry standard!