Beer Stone: How to Remove It and Where it Comes From

The mission of A.C. Technologies is to clean up the draught beer in America. In the brewing industry, that noble mission, however, has scientific complications, implications, and challenges. To begin with, when a person decides to become a brewer, he or she is accepting the probability that, at some time during their career, they will experience “beer stone". Unfortunately, beer stone happens! And it can happen on the inside surface of any brewing vessel, beer line, plate heat exchanger, valve, pump, etc.

What is beer stone?

Simply put, beer stone is a “staining” or sediment of calcium oxalate and protein material on a surface. If allowed to build up, it becomes exceptionally difficult to remove and further allows bacteria to populate the precipitate (which in turn can provide nutrients to the contaminating bacteria for further bacterial growth) which risks negatively affecting beer flavor, beer turbidity or even cause “gushing” of the beer so that the consumer will not experience the beer as the brewmaster intended. Additionally, beer stone will protect contaminating bacteria from removal by usual cleaning until the beer stone is removed. Therefore, a surface build-up of beer stone is impossible to sanitize, will additionally interfere with passivation of the metal surface and, ultimately, will contribute to corrosion of the metal surface.

Where do the components of beer stone come from?

Breaking it down, so to speak, oxalate or oxalic acid is found in malt but not in raw barley. As barley is germinated in the malting process, the concentration of oxalate increases in the barley kernels. Because of this, all types of wort will contain oxalate. Typical brewing salts are, of course, calcium sulfate and calcium chloride. Oxalate has a strong binding affinity to calcium-forming calcium oxalate in the brewing process. Proteins and polypeptides also found in the wort will co-sediment by binding with the calcium oxalate forming the beer stone. Baked on to a surface further exacerbates the difficulty to easily remove it.

How can beer stone be removed?

Beerstone can be efficiently and effectively removed by first breaking down the proteins using a properly formulated, high-quality caustic solution which also contains properly balanced surfactants, wetting, and chelating agents to bind the mineral deposits and which is properly formulated for the surface to be cleaned, such as stainless steel or, in the case of beer dispense lines, specific polymers. Please note that caustic soda purity can vary; with the highest quality having lower levels of impurities such as salt and iron. Such efficient beer stone removers go under the trade names Master Brewers Standard for stainless steel and Draftec beer line cleaner. Such solutions, when regularly used, will not only remove beer stone effectively but also help prevent the further build-up of beer stone.

A.C. Technologies - Clean once, Clean right!

A free sample of Draftec's beer line cleaner is available for professional line cleaners and beer distributors. To request a sample, please email us at info@draftec.com or call us at (888) 226-8228.