ETS Laboratories - Sulfides Panel

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Sulfides Panel

NAME	UNITS	TECHNIQUE	METHOD

diethyl disulfide	ug/L	GC-SCD
Diethyl disulfide is a type of disulfide commonly found in wine, but usually at concentrations below sensory thresholds. They are typically formed after fermentation from oxidation of sulfide or mercaptan precursors. They are a serious concern due to their propensity to revert back to mercaptans. This conversion is often accompanied by an increase in objectionable odors due to the lower mercaptans threshold limits. Disulfides are not responsive to copper without pretreatment to break the disulfide bond.

diethyl sulfide	ug/L	GC-SCD
Diethyl sulfide is usually present in wine at levels below its sensory threshold. However, in higher concentrations is can contribute “rubbery” odors.

dimethyl disulfide	ug/L	GC-SCD
Dimethyl disulfide is a type of disulfide commonly found in wine, but usually at concentrations below sensory thresholds. They are typically formed after fermentation from oxidation of sulfide or mercaptan precursors. They are a serious concern due to their propensity to revert back to mercaptans. This conversion is often accompanied by an increase in objectionable odors due to the lower mercaptans threshold limits. Disulfides are not responsive to copper without pretreatment to break the disulfide bond.

dimethyl sulfide	ug/L	GC-SCD
Dimethyl sulfide, or DMS, is present in almost all wines and is probably a breakdown product of amino acids. At low levels (15 to 20 ppb in whites and 20 to 30 ppb in reds) DMS can contribute "roundness", "fruitiness", or "complexity". DMS concentrations increase with wine age and the "canned corn" or "truffle" sensory characteristics of DMS may develop during bottle aging. At higher levels (>30 ppb for whites and >50 ppb for reds) DMS may contribute vegetative, "cooked cabbage", or "sulfide" smells to wines.

ethyl mercaptan	ug/L	GC-SCD
Ethyl mercaptan is not commonly found in wines above its sensory threshold. Mercaptans, also known as thiols, are commonly found in wines. Their "burnt match" and "rotten cabbage" aromas may be even more pungent and offensive than Hydrogen Sulfide. Although the mechanisms of mercaptan formation are not clear, mercaptans are probably formed during fermentation by reactions involving Hydrogen Sulfide or breakdown of sulfur containing amino acids. Fermenting samples that contain Hydrogen Sulfide usually also contain mercaptans. Under certain conditions, mercaptans may be oxidized to form mono and disulfides. While this may remove the objectionable sensory effects of mercaptans, the effect may be temporary.

hydrogen sulfide	ug/L	GC-SCD
Hydrogen sulfide, or H₂S, is a natural by-product of yeast metabolism. Yeasts form H₂S by reduction of sulfates, sulfites, and elemental sulfur during amino acid synthesis. Problems arise when inconsistent H2S production exceeds its utilization and excess H2S "leaks" into the wine.

methyl mercaptan	ug/L	GC-SCD
Methyl mercaptan is the most common problem sulfide compound found in post-fermentation wines. Mercaptans, also known as thiols, are commonly found in wines. Their "burnt match" and "rotten cabbage" aromas may be even more pungent and offensive than Hydrogen Sulfide. Although the mechanisms of mercaptan formation are not clear, mercaptans are probably formed during fermentation by reactions involving Hydrogen Sulfide or breakdown of sulfur containing amino acids. Fermenting samples that contain Hydrogen Sulfide usually also contain mercaptans. Under certain conditions, mercaptans may be oxidized to form mono and disulfides. While this may remove the objectionable sensory effects of mercaptans, the effect may be temporary.



	The Sulfides Panel tests for some of the most common sulfides that are found in wine. Sulfides are associated with reduction characteristics and can taint a wine due to their unpleasant aroma. Some of the aromas associated with sulfides include burnt rubber, cooked onions, and rotten eggs. Identification and quantitation of these compounds is useful in determining the most appropriate methods for remediation and to determine the efficacy of those treatments. For more information on Sulfide analysis, please Click Here.

MINIMUM VOLUME	CONTAINER TYPE	OTHER

375 mL	Glass Bottle	Container Should Have Minimal Headspace

NUMBER OF SAMPLES SUBMITTED We achieve economies of scale here at ETS based on the volume of samples processed at a given time. As a consequence we are pleased to pass these savings on to our customers, offering discounts for multiple sample submissions. These discounts apply only to samples submitted at the same time.	1	2-10	11+

Fee Per Sample	$121.00	$110.00	$99.00