Sherry is fortified wine from the Spanish region of Jerez. Unlike port, sherry is fortified at the end of fermentation, which doesn't interrupt the fermentation process. Although sherry comes in a broad range of flavors and colors, there are two basic styles of sherry: fino and oloroso. These styles are separated in the criadera (nursery) depending on the presence of a beneficial surface yeast called flor. Those wines that develop flor are usually destined to become the paler, lighter fino style of sherry that has a tangy taste and is best when drunk young. The wines that are without flor are earmarked for oloroso, which is typically made dry, is aged longer than most sherries, and has a nutty, raisiny flavor. The solera system of fractional blending plays an important role in sherry production. It's sort of a wine pyramid scheme, where the youngest casks of sherry—called butts—are stacked on top of older butts in a descending order of age, with the oldest butts at the bottom. The young wines revive and freshen the solera, keeping the beneficial surface flor alive, while the older wines add nuance and character to the young wine. There are several styles of sherry, listed here from the fullest-bodied to the lightest: cream sherry, pale cream, oloroso, palo cortado, amontillado, fino, and manzanilla.