We did an extensive amount of research on packaging when we first launched the Kalona SuperNatural brand, and what we found is that the environmental benefits of glass vs plastic are over-estimated. Specifically:
In the dairy industry, glass bottles must be made of virgin--not recycled--glass.
Glass bottles require return shipping which has a larger carbon footprint then plastic going only one-way.
Washing and cleaning bottles requires additional facilities and waste.
Glass bottles frequently break and many retailers do not like glass packaging due to breakage and extra weight.
Please note that when choosing our bottles, we picked packaging that are BPA-free and BPS-free. The clear plastic bottles also allow customers to see the condition of the milk, and our 16oz, 32oz, and 64oz bottles contain a special UV inhibitor that helps protect the milk from light (oxidation.)
We are hopeful that packaging companies will develop new, more sustainable packaging that we can use in the future. They are working on it!