sulfur; sulphur
There are two distinct sulfurous characteristics that affect a wine’s smell. One, which occurs when there are excessive amounts of sulfur dioxide, has the smell of a burnt matchstick just after it’s lit. This pungent odor is often accompanied by a prickling sensation in the back of the throat and upper part of the nose. A sulphur dioxide characteristic will generally dissipate through aeration, either by decanting the wine or swirling it in the glass. The other form of sulfur that can negatively influence wine is hydrogen sulfide (H2S), which creates the distinctively foul odor of rotten eggs, sometimes rubber. H2S that stays too long in wine combines with other constituents to form mercaptans (which smell skunky) and, eventually, disulfides, which reek of sewage.
The New Wine Lovers Companion, 2nd Edition, by Ron Herbst and Sharon Tyler Herbst. Copyright © (1) 2003, 1995 by Ron Herbst and Sharon Tyler Herbst. Reprinted by arrangement with Barron's Educational Series, Inc.