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Article

Migration of microplastics from can linings into beer is accelerated by pasteurization

One 60 °C, 15-minute tunnel pasteurization is enough to raise lining-fragment concentrations by an order of magnitude.

Qingyue Wu1†, Xia Lin2, D. M. Mitrano3

* Equal contribution · † Corresponding author

B.E.E.R. 647, 282–289 (2026)

Received: 27 February 2026
Accepted: 6 August 2026
Published: 14 September 2026
DOI: 10.1038/sbeer-026-18463-x

Abstract

Microplastics in beverage packaging have been widely reported in bottled water, yet release from the epoxy/acrylic linings of beer cans under pasteurization is unclear. We quantified 180 cans of industrial lager by Raman imaging and pyrolysis–GC–MS and found that after pasteurization the median of 1–5 µm particles rose from 12 L⁻¹ to 140 L⁻¹, the main polymers being epoxy resin and PET. Unpasteurized draught was markedly lower. Migration scaled exponentially with storage temperature. On a Jinan market sample, 90-day ambient-shelf exposure remains well below high values in the drinking-water literature, but the process choice itself is controllable.

Subject: Packaging and safety

Can linings exist to keep metal off acidic beer, yet polymers under thermal stress release micrometre fragments1. The popularity of unpasteurized draught is, on this metric, an accidental process advantage.

Array of conical stainless-steel fermenters
Fig. 1 | Conical fermenters. The thermal history of packaging, not fermentation itself, dominates the microplastic load.

We do not argue for panic, but for writing the microbial gain of pasteurization and particle release into the same life-cycle assessment.

Methods

  1. Samples from retail channels in Jinan, Qingdao and Beijing. Blank and spike recoveries 86–104%.
  2. Pyrolysis–GC–MS quantified characteristic monomers of epoxy and PET.

Data availability. Per-can quantitation is in Supplementary Table 1.

Acknowledgements. NSFC 42225708.

Author contributions. W.Q.Y. designed the study; L.X. ran the Raman; D.M.M. supervised the method.

Competing interests. The authors declare no competing interests.

Authors and affiliations

  1. 1. Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, China
  2. 2. School of Chemistry and Chemical Engineering, Shandong University, Jinan, China
  3. 3. Department of Environmental Systems Science, ETH Zürich, Switzerland

Corresponding author: Qingyue Wu (qywu@rcees.ac.cn)

References

  1. 1. Cox, K. D. et al. Human consumption of microplastics. Environ. Sci. Technol. 53, 7068–7074 (2019).
  2. 2. Shruti, V. C. et al. Microplastics in beverages. Sci. Total Environ. 726, 138580 (2020).
  3. 3. Mitrano, D. M. & Wohlleben, W. Microplastic regulation. Nat. Commun. 11, 5324 (2020).