acetaldehyde [as-ih-TAL-duh-hide]

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A natural element found in grapes and wine, acetaldehyde is colorless, volatile, and water-soluble. It has a pungent fruitlike odor and is present in small amounts in good TABLE WINE and in high amounts in oxidized wines. OXIDATION is a detriment in a normal table wine but intentional in wines like SHERRY or MADEIRA. Most acetaldehyde eventually converts to ETHANOL, the ALCOHOL found in wine. If oxygen is introduced too fast or in excessive amounts, the production of acetaldehyde can temporarily cause a reaction like BOTTLE SICKNESS or, worse, give wine a permanent sherrylike.