I noticed in whole foods a while back that they are selling store brand apple juice/apple cider at whole foods in 1g glass carboys! There aren't any preservatives that would stop fermentation, and thus far my 3 piece airlock and standard issue rubber plug fit snugly into the tops of 'em If you've been wanting to experiment with cider recipes, I'd suggest grabbing a couple of these- I'm already reusing my first little carboy for mead and it's working great!