The team sampled 12 brands of beer from large brewers and craft brewers from around the Great Lakes. In every sample microscopic plastic fibers and particles were detected. Most of the fibers were smaller than five millimeters in length.

Wattenberg said what was interesting about the beer samples was a discrepancy in the amount of plastic contained in the final product when compared with the water used to make it.

https://www.wpr.org/minnesota-researchers-find-microplastics-beer-made-great-lakes-water