Fortified wine da Fonseca, the founder of the oldest table wine company in Portugal dating back to 1834. Port wine (also known simply as Port) is a fortified wine from the Douro Valley in the northern provinces of Portugal. It is typically a sweet red wine, but also comes in dry, semi-dry and white varieties. Sherry is a fortified wine made from white grapes that are grown near the town of Jerez, Spain. The word "sherry" itself is an anglicisation of Jerez. In earlier times, sherry was known as "sack" (from the Spanish "saca", meaning "a removal from the solera"). In the
Clarification and stabilization of wine that has not been put through complete malolactic fermentation may undergo it in bottle, reducing its acidity, generating carbon dioxide, and adding a diacetyl butterscotch aroma. "Brettanomyces" yeasts add 4-ethylphenol, 4-ethylguaiacol and isovaleric acid horse-sweat aromas. These phenomena may be prevented by sterile filtration, by the addition of relatively large quantities of sulfur dioxide and sometimes sorbic acid, by mixing in alcoholic spirit to give a fortified wine of sufficient strength to kill all yeast and bacteria, or by pasteurization. Pasteurization gives a kosher wine of the type called "mevushal", literally "cooked" or "boiled", that can be handled by non-Jews