Changes

Usually, only pasteurized sour beer is canned due to the danger of over-carbonating canned beer, however, some brewers have been experimenting with canning mixed fermentation beer and allowing the beer to naturally carbonate in the cans. It is recommended that brewers contact their can supplier to verify that the plastic liners for the cans are rated to handle the pH [[Titratable Acidity]] of sour beer (3-4 pH; kettle soured or otherwise) and to find out the lifespan of the cans. Cans have been found to preserve some hop compounds such as myrcene and caryophyllene better than bottles because bottle caps can strip some of these compounds <ref>[https://onlinelibrary.wiley.com/doi/full/10.1002/jib.667 Kemp, O., Hofmann, S., Braumann, I., Jensen, S., Fenton, A., and Oladokun, O. (2021) Changes in key hop-derived compounds and their impact on perceived dry-hop flavour in beers after storage at cold and ambient temperature. J. Inst. Brew., https://doi.org/10.1002/jib.667.]</ref>. One study by [https://www.tandfonline.com/doi/pdf/10.1080/03610470.2024.2395677 Sheehan et al. (2024)] examined 9 different sour beers canned with 4 different liners with their maximum thickness available from the manufacturer: BPA based epoxy, acrylic, and two versions of BPA-NI epoxies. They aged the cans up to 48 weeks at 20°C. Out of the 9 different sour beers examined, they found that one sour beer with 7.55 g/L lactic acid (the other sour beers that did not heavily erode the liners had 5.84 g/L or less lactic acid) and one sour beer with 9.01 g/L acetic acid eroded the liners and increased the dissolved aluminum to elevated levels of 9.3 mg/L and 43.2 mg/L. This occurred at the 48 week mark. The European Food Safety Authority advises consumption of no more than 1 mg/kg body weight per week; the World Health Organization advises a limit of 2 mg/kg of body weight per week. Aluminum is regularly used as a food additive in small amounts, and most aluminum consumed is filtered by the kidneys. Regular exceedence of the weekly intake can increase the risk of health impairments, including developmental toxicity, neurotoxicity, and effects on the urinary tract and potentially the digestive track. There is no consistent evidence linking aluminum exposure from food and water to Alzheimer's disease or breast cancer. All 4 liner types were eroded by the two beers and did not comparatively protect the beers from aluminum contamination. For the beer with high acetic acid, which was deemed not sellable by the brewery that produced it and dumped, consumption of a 355 mL (12 oz) serving per day would equate to ~15 mg/day aluminum, or ~100 mg/week. This value approaches the World Health Organization recommended total weekly intake of <2 mg Al/week per kg body weight, or <150 mg Al/week for a 75 kg person. Can erosion was not correlated with pH, but it was correlated with [[Titratable Acidity]]. It is recommended that breweries send samples of their beer to their can supplier to have the beer tested to make sure that the liner will not erode <ref>[https://www.tandfonline.com/doi/pdf/10.1080/03610470.2024.2395677 Matthew Sheehan, Austin Montgomery, Julie M. Goddard & Gavin L. Sacks (15 Oct 2024): Lactic and Acetic Acids in Sour Beers Promote Corrosion During Aluminum Beverage Can Storage, Journal of the American Society of Brewing Chemists, DOI: 10.1080/03610470.2024.2395677.]</ref><ref>[https://pmc.ncbi.nlm.nih.gov/articles/PMC3998638/ Pineton de Chambrun G, Body-Malapel M, Frey-Wagner I, Djouina M, Deknuydt F, Atrott K, Esquerre N, Altare F, Neut C, Arrieta MC, Kanneganti TD, Rogler G, Colombel JF, Cortot A, Desreumaux P, Vignal C. Aluminum enhances inflammation and decreases mucosal healing in experimental colitis in mice. Mucosal Immunol. 2014 May;7(3):589-601. doi: 10.1038/mi.2013.78. Epub 2013 Oct 16. PMID: 24129165; PMCID: PMC3998638.]</ref><ref>[https://www.sciencedirect.com/science/article/abs/pii/S0045653521030289#:~:text=Aluminum%20exposure%20can%20damage%20the,stability%20of%20the%20biological%20barrier Wudi Hao, Chenyu Hao, Chengrong Wu, Yuqing Xu, Cuihong Jin,Aluminum induced intestinal dysfunction via mechanical, immune, chemical and biological barriers, Chemosphere. Volume 288, Part 2, 2022, 132556, ISSN 0045-6535. https://doi.org/10.1016/j.chemosphere.2021.132556.]</ref>. See also [https://www.facebook.com/groups/MilkTheFunk/posts/9393681103993353/ this post on MTF].