Undrinkable? Maybe. Soon to be unbreakable? Probably.

There's a wide range of glass thicknesses used in the wine business. Bronco Wine already packages Charles Shaw wines in very thin/light bottles, which might explain why there's so much breakage in the stores. Moving to PET packaging would improve margins and reduce breakage.

Anyone who's worked in a Trader Joe's store knows that several times a day, there's a wet cleanup in the wine department—usually no great loss, as it's just a bottle of Two-buck Chuck. 

That may soon be happening a lot less frequently, because Bronco Wine, the supplier of TJ's most famous plonk, is experimenting with plastic bottles. The bottles are supplied to Bronco by a company called Amcor. They're made from PET, which stands for polyethylene terephthalate, lined with a silicone oxide barrier (trademark: Plasmax). The purpose of the Plasmax inner coating is to prevent the oxidation through the package.

Currently, Bronco is testing the packaging with its Green Fin white wine, which is packaged only for Trader Joe's. The plastic bottles are lighter than glass (of course) and are fully recyclable. While crew members in stores will appreciate reduced breakage, there are a number of advantages including faster fill-rates (the rate at which bottles can be filled, capped, and put into cartons in the plant) and lighter shipping weights.

PET is the same plastic used for a lot of the small bottles of wine served on airplanes (though not usually in First Class!) If you've bought Jack Daniels in a plastic bottle, it was also made of PET.