Charmat, or tank method, is the process of turning inexpensive bulk wine into inexpensive bulk sparkling wine. For good sparkling wine, the secondary fermentation takes place in the bottle, while the cheap stuff you guzzle at weddings ferments in huge tanks using the tank method, bulk method, cuve close (French for "closed tank"), or charmat method. Here's how it works: Yeast, sugar, and a lot of (usually) inexpensive white wine are thrown together in a several-thousand-gallon tank, which is then sealed for a few weeks to allow the wine to ferment under pressure (hence, all those carbon dioxide bubbles). The wine is then filtered and bottled under pressure and slapped with a label that, by law, must say either "charmat" or "bulk" (as opposed to "m├ęthode champenoise" or "fermented in this bottle"). You can usually tell you're drinking charmat-style sparkling wine if the bubbles are larger than bottle-fermented sparkling wine. The process was named after its inventor, Frenchman Eugene Charmat.