mercaptan

Lemma

mercaptan

Etichetta di dominio

EN

Etichetta grammaticale

n.

Definizione

Wine fault that can be cured by assiduous racking and that presents a kunky smell resulting from yeast reacting with the lees. 1

Nota

Volatile sulfur compounds, and specifically mercaptans, are […] largely responsible for the olfactory defect known as ‘reduction’. […] [Mercaptans, also known as thiols, are] a large group of very smelly sulfur compounds. Terms such as cabbagey, rubbery, struck flint or burnt rubber are used as descriptors. If hydrogen sulfide isn’t removed quickly, it can result in mercaptan production. This is a big worry for winemakers.
[…] sulfides present in the wine at bottling necessitate a very small level of oxygen ingress through the closure, otherwise they can become reduced to thiols. Because sulfides are less smelly, it is possible for a wine that is clean at bottling to taste reduced after bottling if the closure doesn’t permit enough oxygen ingress. So the use of a closure, such as cork, which does allow a little oxygen ingress (but not too much) is a necessary concession to the vagaries of sulfur chemistry. Of course, we’d rather not have the sulfides in the wine at all, which would then avoid problems with reduction to mercaptans at a later stage. 2

Contesto

When a wine is strangely lacking in aroma, low level sulphur compounds should be suspected. The penny test will confirm that suspicion for H2S or mercaptan. Such wines should be considered flawed. 3

Trascrizione fonetica

UK [məːˈkapt(ə)n] US [mərˈkæpˌtæn] 4

Sinonimi e Antonimi

Synonym: thiol 5

Abbreviazioni
ND
Etimologia

< German Mercaptan (W. C. Zeise 1834, in Ann. der Physik u. Chem. 31 378) < mer- (in post-classical Latin mercurius) + captan- (in classical Latin captāns, present participle of captāre to take, seize): Zeise explains the formation as follows ‘Mercaptan (d.h. Corpus mercurium captans).’ 6

Etichetta di paese
ND
Ente

Università degli Studi di Genova

Data della scheda
Mon Sep 15 00:00:00 2008
Autore

revisione di Chiara Barbagianni

Fonti

1 : «http://www.grapestomper.com/wineglossary.html», (24/11/2011)

2 : «http://www.wineanorak.com/mercaptansinwine.htm», (24/11/2011)

3 : «www.bcawa.ca/winemaking/flaws.htm», (29/07/2008)

4 : «http://www.oed.com/view/Entry/116613?redirectedFrom=mercaptan#eid», (24/11/2011)

5 : «http://chemicalland21.com/industrialchem/solalc/ETHYL%20MERCAPTAN.htm», (24/11/2011)

6 : «http://www.oed.com/view/Entry/116613?redirectedFrom=mercaptan#eid», (24/11/2011)

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