Cork is an impermeable buoyant material. It is the phellem layer of bark tissue which is harvested for commercial use primarily from Quercus suber (the cork oak), which is native to southwest Europe and northwest Africa. Cork is composed of suberin, a hydrophobic substance.

Wine corks, however, generally sell for about 10 cents each.

In the early 21st century, the problem of cork taint became prevalent, leading many producers to stop using corks in favor of alternatives. Screw caps became especially prominent in Australia and New Zealand by 2010. Most cork was sourced from around the Mediterranean Basin, far from the Oceanian countries.

1) Other than wine or beer, what is bottled using corks? - High-end bourbon, quite often. High-end olive oil, on occasion.