Plastic is just too expensive, no matter how you look at it.

wnpbbThat’s what leading U.S. brewer Anheuser-Busch found when it experimented in the summer of 1998 with bottles made from polyethylene naphthalate (PEN). The biggest advantage of the PEN bottle was that it stayed rigid under heat, which allowed for in-bottle pasteurization.

“You can pasteurize the bottle with beer in it, and if you get it to the place where it’s going to be drunk fast enough, it’s a quite excellent bottle,” says Allan Silverman, a vice president with the Constar unit of Crown Cork & Seal, Philadelphia, which blowmolded the bottles.

Time was the major problem. Although PEN has a tighter molecular structure than PET, its barrier still is insufficient, meaning it doesn’t yield a good enough shelf life, Silverman says: “You could have given it away or charged a million dollars – it wouldn’t have worked. The barrier isn’t good enough.”

To make plastic bottles with a sufficient barrier requires a multi-layer structure. These designs tend to push the bottle’s price significantly beyond glass and aluminum.

The price ain’t right

Price was the reason Anheuser-Busch recently terminated another trial of a plastic beer bottle: a test market in Dallas and Phoenix, Ariz., convenience stores. The three-layer bottle comprises a layer of oxygen-scavenging copolyester between two layers of PET, with more oxygen-scavenging material in the closure liner.

Anheuser-Busch concluded the test market after six weeks because of disappointing