Advertisement
Research Report

Redox Control of a Chardonnay Fermentation to Limit the Conversion of Elemental Sulfur to Hydrogen Sulfide

Samantha Young, Caroline Merrell, Torey Arvik, Roger Boulton
Am J Enol Vitic.  2025  76: 0760021  ; DOI: 10.5344/ajev.2025.24071

Abstract

Background and goals The formation of hydrogen sulfide (H2S) during wine fermentations that contain residual elemental sulfur continues to be a significant and chronic fermentation problem occurring in wineries worldwide, requiring additional treatments that often contribute to long-term wine instability and/or the loss of wine quality and commercial value. This study investigated the possibility of preventing H2S formation during wine fermentation by controlling the redox potential during fermentation.

Methods and key findings Triplicate juice volumes were fermented with the same yeast strain, nutrient conditions, and temperature. Three fermentations were controlled so that the redox potential during fermentation would not fall below +150 mV (silver/silver chloride [Ag/AgCl] reference). Three others were fermented without any intervention. The controlled redox potential fermentations had 10% of the H2S found in the uncontrolled cases at peak formation, and 2% of that found in the uncontrolled cases at the end of fermentation. The controlled redox potential replicates also completed fermentation 2 days earlier. The wines from the controlled redox fermentations had a glutathione content of 552.4 mg/L, compared to 252.4 mg/L in the reference fermentations.

Conclusions and significance The outcome of this experiment is the first demonstration of effectively limiting the conversion of elemental sulfur into H2S by regulating the redox potential throughout fermentation. It also confirms previous results that this control action can lead to earlier completion of fermentation by modifying the fermentation ability of nongrowing cells. It demonstrates the interaction between the redox potential of the juice and yeast metabolism that resulted in the formation of glutathione under the controlled redox condition.

Introduction

Elemental sulfur has been associated with hydrogen sulfide (H2S) formation during wine fermentation for more than 150 yr (Nessler 1885). The source of the sulfur is attributed to its use in viticulture to prevent powdery mildew, and the burning of sulfur sticks to sanitize cooperage (Widmer 1936). Microscopic observations of elemental sulfur particles attached to and within yeast membranes led to the suggestion that yeast metabolism was directly responsible for H2S formation (Schanderl 1959). Increasing interest in returning to elemental sulfur applications onto grapevines as organic farming methods are adopted has led to studies of residual sulfur levels on grapes and in juices prior to fermentation. Reports quantifying the residues of elemental sulfur on grapes indicate levels of 3.4 mg/L from washed clusters (Thomas et al. 1993) and 2 μg/L in juice after grape pressing (Kwasniewski et al. 2014).

Levels of elemental sulfur at or above 1 mg/L delayed the onset of fermentation; low levels (below 0.1 mg/L) did not (Schanderl 1959). The author noted differences between yeast strains in their responses to the presence of elemental sulfur. A later study showed that finer forms of elemental sulfur resulted in higher levels of H2S formation and that different yeast strains formed different amounts of sulfide; in an example fermentation curve, the rate of H2S formation coincided with the rate of carbon dioxide evolution and the minimum of the oxidation-redox potential (ORP) (Rankine 1963). That same study also identified traces of ethanethiol and suggested that H2S might be a precursor for the formation of other thiols. Others studying H2S formation during, and resulting from, wine fermentations confirmed that H2S formation depends on yeast strain and sulfur type (Acree et al. 1972, Schutz and Kunkee 1977). One of these studies concluded that yeast and elemental sulfur particles must be in contact to form H2S (Schutz and Kunkee 1977).

Most studies on H2S formation during fermentation have used trapping solutions or lead acetate tubes to quantify H2S levels (Rankine 1963, Acree et al. 1972, Schutz and Kunkee 1977, Thomas et al. 1993, Park 2001, 2008, Kwasniewski et al. 2014, Allison et al. 2022). Others used gas chromatography-mass spectrometry to quantify volatile sulfur compounds (VSCs) in the headspace (Rauhut and Kürbel 1994, Rauhut et al. 1999), or a sulfur-specific detector (Herszage and Ebeler 2011).

The formation of H2S, methanethiol, and other sulfur volatiles in marshland soils was shown to be a function of redox potential, with H2S and methanethiol entirely eliminated when the redox potential was held above 0 mV, relative to the standard hydrogen electrode (SHE) (Devai and DeLaune 1995). Studies in wine fermentations found evidence of S-methyl thioacetate as a marker for the presence of elemental sulfur during fermentation (Rauhut and Kürbel 1994), and that other thiols and polysulfides are formed in conjunction with H2S during and after fermentation (Rauhut et al. 1999, 2001, Dekker et al. 2022, Kinzurik et al. 2016, Araujo et al. 2017).

Small-scale fermentations have been used for most H2S studies, with juice volumes of 250 to 500 mL (Rankine 1963), 50 mL (Acree et al. 1972), 1 L (Thomas et al. 1993), 50 mL (Dekker et al. 2022), 625 mL (Park 2008), 15 L (Butzke and Park 2011), 30 L (Kwasniewski et al. 2014), and 100 mL and 1 L (Jastrzembski et al. 2017). The volume used in the Schutz and Kunkee (1977) study is not known.

The hypothesis forming the basis of this work is that H2S formation develops in sulfur-containing solutions at low redox potentials through a chemical reaction, external to the yeast cells, and the extent of this reaction can be limited by the control of the redox potential during fermentation. This hypothesis implies that there are effects on sulfide formation due to both yeast strain and juice composition (Rankine 1963). The commonly held view is that this formation is due to yeast cellular metabolism and this is why the extent of sulfide production differs significantly by yeast strain. The role of yeast in the present hypothesis is caused by their modification of the redox potential during fermentation, sometimes causing the redox potential to fall to a minimum of between −100 to −200 mV (SHE). This low redox potential environment then favors the partial chemical reduction of elemental sulfur into H2S, external of the cells.

There is presently no known means to prevent or limit H2S formation during wine fermentation, even when elemental sulfur is not present. The conclusion that adding yeast assimilable nitrogen (YAN) prevents H2S formation (Vos and Gray 1979, Jiranek et al. 1995, Nowak et al. 2013) is often contradicted by experiments in other juices (Ugliano et al. 2009, 2011, Kraft et al. 2023), including in this study and in our research and commercial winemaking experience.

Materials and Methods

Juice preparation

Chardonnay juice concentrate was purchased (California Concentrate Company), received at 68 Brix, then thawed and diluted with water to 24 Brix. YAN was 257 mg/L and free SO2 was less than 1 mg/L. Elemental dusting sulfur (25 mg/L; Special Electric Sulfur, Wilbur-Ellis) and a fermentation supplement (0.5 g/L; SpringFerm, Fermentis) were added to the juice. The juice was then divided into six, 9-L fermentation lots (three uncontrolled fermentations and three redox-controlled fermentations) in 20-L plastic vessels. Each fermentation was inoculated with Lalvin RC212 yeast (0.25 g/L; Scott Laboratories) following rehydration in 40°C (104°F) water, together with GoFerm (0.31 g/L; Scott Laboratories).

Fermentations

Wines were allowed to ferment at ambient temperature. Fermentation temperatures ranged from 20 to 25°C, averaging 22°C (67 to 77°F, averaging 72°F). The fermentating musts were not mixed, apart from the air introduced into the controlled-redox replicates. Redox potential was measured each minute throughout the fermentation using Hamilton EasyFerm ORP probes (silver/silver chloride [Ag/ AgCl] reference; redox potential [Eh] equal to 222 mV [SHE]) (Janz and Taniguchi 1953). Redox probes were submerged in the fermenting must through a port in the vessel lid. Redox control was obtained via a programmable logic controller that measured ORP and opened a solenoid valve to a compressed air tank when the reading was below 150 mV (SHE). When needed, air was delivered in 30 sec pulses, with a 2 sec rest between pulses. Air valves remained closed when the ORP was above 150 mV (SHE). Filtered, compressed air was delivered to each controlled fermentation through an aeration stone.

Sampling

Samples for H2S analysis were collected once or twice per day, depending on fermentation stage. Samples were collected by opening the fermentation vessel lid, collecting a sample, and immediately closing the lid. Total soluble solids and temperature measurements were performed using a handheld density meter (DMA 35, Anton Paar).

H2S analysis

H2S was measured via gas detection tubes (Gastec 4L, 4LL, 4LB; Grainger), following a modified Monier-Williams SO2 protocol (Allison et al. 2022). Briefly, 60 mL of fermenting wine was added to a 100-mL sample flask fitted with a fritted impinger. An SO2 scrubber (Gastec 5LA SO2 detection tube) followed by an H2S gas detection tube was connected to the outlet of the impinger. Samples were sparged with nitrogen to volatilize the H2S through the detection tubes. The sample was allowed to sparge for 15 min for 4LB and 4LL tubes, and for 20 min for 4L tubes. The additional time was required to sufficiently volatilize all the H2S in high concentration samples using 4L tubes. Quantification was achieved by measuring the length of color change on the tube. Calibration curves were developed using sodium sulfide nonahydrate (Fisher Scientific). Calibration ranges were 1.2 to 25 μg/L (4LB), 5 to 280 μg/L (4LL), and 20 to 540 μg/L (4L).

Total sulfhydryl analysis

Reduced glutathione was measured as the total sulfhydryl concentration at 252.4 mg/L in juice, using the method of Kontogeorgos and Roussis (2014).

Results

The maximum concentration of H2S occurred between 1 and 2 days after the onset of active fermentation. The maximum H2S concentrations were observed ~12 hr after the maximum fermentation rate of each treatment. The fermentation density curves and the formation of H2S are shown in Figure 1, and the redox potentials during these fermentations are shown in Figure 2. The maximum H2S concentrations and the H2S concentrations at the end of active fermentation were shown to be significantly different (Table 1).

Figure 1
Figure 1

Density and concentration of hydrogen sulfide (H2S) curves for controlled (red, brown, black) and uncontrolled (yellow, green, blue) redox fermentations.

Figure 2
Figure 2

Individual redox potential traces for controlled (red, brown, black) and uncontrolled (yellow, green, blue) redox fermentations. Spikes are due to air introduction when sampling for total soluble solids and hydrogen sulfide analyses.

View this table:
Table 1

Maximum hydrogen sulfide (H2S) concentrations and those at the end of fermentation for controlled and uncontrolled redox fermentations. Values within the same column not sharing the same letter are significantly different at p < 0.05.

Discussion

In this work, the control of the redox potential was set to be constant to remove the effects that its changing pattern might have on the fermentation outcome. Controlling the redox potential in this way limited H2S formation by a factor of 10 at the peak of its formation, and by a factor of 50 at the end of fermentation (Figure 1 and Table 1). This demonstrates that the redox potential of the external solution is the major factor influencing the formation of H2S from elemental sulfur during wine fermentation, and that controlling the redox potential can limit this formation.

H2S formation during yeast fermentations in the absence of elemental sulfur is attributed to the reduction of external sulfite from bound forms of sulfite that are transported into yeast cells (Stratford and Rose 1985). Formation of H2S by native and wine strains of Saccharomyces cerevisiae has been shown to be a common trait when elemental sulfur is not present during fermentation (Kumar et al. 2010). Reviews of possible sources for VSC formation (including H2S) during wine fermentation are available (Smith et al. 2015, Müller and Rauhut 2018). The discussion of redox reactions involving transition metals and of dissolved oxygen treatments on VSC formation has an alternative understanding of the redox potential during fermentation and its role in the conversion of elemental sulfur to H2S.

It has now been shown that labeled sulfur in sulfate first appears in H2S during fermentation and is the precursor in the formation of ethanethiol, S-ethyl thioacetate, and diethyl disulfide that also contain labeled sulfur (Kinzurik et al. 2016). It was confirmed that the formation of H2S was strain-dependent, and the formation of S-methyl and S-ethyl thioacetates was identified in addition to H2S in fermentations when elemental sulfur was present (Rauhut and Kürbel 1994). The presence of elemental sulfur and the formation of H2S have been further linked to the formation of 3-mercaptohexenal when suitable levels of 3-hexenal exist in the juice of Sauvignon blanc (Araujo et al. 2017, Sarmadi et al. 2024).

The control of the redox potential in this trial is not exact because the time of the pulse and the volume of air delivered cannot be calculated, based on juice composition and yeast strain prior to the experiment. Significant variation in the redox response caused by juice composition in other fermentations has been observed. The air additions in this trial were insufficient to achieve the setpoint potential throughout the middle period of the fermentation. However, the potential was generally higher by 100 to 200 mV above the uncontrolled fermentations and this alone was sufficient to provide the desired outcome in terms of limiting H2S formation.

Alternative descriptions for this overall reaction range from the incorporation of sulfur entities (metal complexes, or S8 rings) into the cell and the modification at internal cell conditions (pH and Eh) (favored by Schanderl [1959]; referred to here as the “internal reaction” case), to the chemical reaction of sulfur entities at the solution conditions (pH and Eh), external of the cell (favored by Rankine [1963] and the authors of the present study; referred to as the “external reaction” case). Another alternative description is the binding of sulfur entities to the cell wall, where the reaction takes place at the conditions of the interface (favored by Schutz and Kunkee [1977]; referred to as the “interface reaction” case). All three descriptions would be yeast-strain dependent, with the external reaction and interface reaction cases being subject to the pH and Eh of the external medium. The yeast strain effect in the internal reaction and interface reaction cases is likely related to membrane transport and binding properties of the cells. The internal reaction case may also be sensitive to the expression of redox-related genes within the cells. The yeast strain effect in the external reaction case is an indirect one, caused by the redox potential pattern developed in the juice, by the yeast, during the fermentation. This pattern would be influenced by the juice composition, possibly modified during fermentation and its associated redox buffering. Future studies might investigate these alternative descriptions further, utilizing the ability to hold the redox potential constant during those fermentations.

A quote from Rankine (1963) is poignant: “The results of this and other experiments with yeasts producing different quantities of hydrogen sulphide indicated that production of hydrogen sulphide is greater with yeasts which ferment rapidly and bring about a rapid lowering of the redox potential”. We agree, but suggest that it is the value of the redox potential, below some threshold, that is influencing the production of H2S, not the speed at which the potential is lowered.

Evidence of the external redox potential influencing the internal redox potential of cells has been found in Escherichia coli (De Graef et al. 1999). These authors suggested a link between the external redox potential and the internal redox potential, which determined the ratio of NADH to NAD+ within these cells. The external redox potential has also been shown to influence the carbon flux and electron flow (Riondet et al. 2000) in the same organism. External stresses are known to alter the internal redox potential in a compartmental manner (Ayer et al. 2013), and cell aging effects are related to redox homeostasis in S. cerevisiae (Ayer et al. 2014). The response of S. cerevisiae cells in their production and release of glutathione in the presence of hydrogen peroxide (H2O2) has been reported (Izawa et al. 1995), as has their being affected by environmental conditions (Perrone et al. 2005). We are unaware of any similar reports of the effects of redox potential on compartmentation, gene expression, or metabolic effects in S. cerevisiae under wine fermentation conditions.

The choice of a setpoint for the solution potential, Eh, of +150 mV on the Ag/AgCl electrode (or −72 mV, SHE) for this experiment is an approximation based on the standard midpoint potential, E0, of the half reaction,

S0+2H++2e=H2SE0=+140 mV(SHE, pH=0)

which when adjusted to pH 3.5 using −59.16 mV/pH, this becomes E′0 of −67.1 mV (SHE), or 154.9 mV (Ag/AgCl). Values reported by various sources for the E0 of the S/H2S couple range from +140 to +171 mV (SHE) with a recent value of 144 mV (Bratsch 1989).

The Pourbaix diagram for sulfur also indicates that the equilibrium potential between solid sulfur and H2S vapor ranges between −50 to −100 mV (SHE) for solutions with a pH of 3.0 and 4.0, respectively, and −75 mV at pH of 3.5 (Pourbaix 1974). Taking both equilibrium values into account, the value of −72 mV (SHE), or +150 mV relative to the Ag/AgCl electrode, was chosen for the setpoint of the control system. Previous wine studies (Nelson et al. 2023) have estimated that at −40 mV (SHE) and typical juice pH, 99.9% of the sulfur is in the oxidized form in a reactive medium.

This is not necessarily the optimum potential setpoint from a kinetic or metabolic perspective, and future studies might investigate the role of this value on H2S formation, with the possibility of finding a redox potential value that can limit the formation even further and perhaps also optimize other thiol formation and sensory outcomes. The resistance to the control action, that is, the redox buffer capacity, in different juices and at different temperatures might lead to the adoption of higher setpoint potentials for different juices, timing, and fermentation practices. Future trials coupled with comprehensive analytical capability might investigate the optimization of the control strategies further.

Because the solution potential of the mixture is also a function of pH and temperature, setpoint values for fermentations between pH 3.0 and 4.0 can be developed and temperature corrections can be estimated for the different temperatures used in white and red wine fermentations.

In a study of wine fermentation with added elemental sulfur, the peak in H2S concentration occurred when the redox potential fell to a minimum of approximately +100 mV (standard calomel electrode) or −150 mV (SHE) (Rankine 1963). A maximum in H2S formation has been reported at −100 mV (SHE), while in other research that studied a cattle manure treatment system, almost none was found at 0 mV (Beard and Guenzi 1983). These authors showed that the concentrations of VSCs could be lowered by controlling the redox potential to 0 mV (SHE) and above, by bubbling O2 gas. They noted that potentials of −100 mV (SHE) and above were previously considered to be needed to prevent H2S formation; their results showed that both H2S and methanethiol formation were prevented at 0 mV. VSC formation has also been related to the prevailing redox potential in marshland soil suspensions (Devai and De Laune 1995). For potentials held above −50 mV (SHE), the rate of H2S formation was less than a tenth that of the lower potential conditions. A similar effect of less formation at potentials above 0 mV was shown for methanethiol, carbonyl sulfide, dimethyl disulfide, and carbon disulfide. Redox potential has been used as the control variable in preventing sulfide formation in waste slurry treatment by applying ozone (Hjorth et al. 2012). The H2S emission was lowered by more than 99% by maintaining the potential at −80 mV. Other researchers were able to control the potential at +215 mV on an Ag/AgCl scale (−55 mV, SHE) during a wine fermentation using only air additions (Killeen et al. 2018), which formed the basis for this study.

The choice of 150 mV, −72 mV (SHE) used for the potential setpoint in these experiments was a compromise between holding the potential close to the Eh estimate for the elemental sulfur to H2S reaction, close to −50 mV (Devai and De Laune 1995), and a desire to have a low quantity of added air.

While a detailed analysis of headspace volatiles was not performed in this trial, a limitation of the formation of methane- and ethane-thiol and methyl- and ethylthioacetate might also be expected. Previous studies have shown the formation of alkyl thio-acetates in conjunction with H2S formation during wine fermentation (Rauhut and Kürbel 1994, Rauhut et al. 1999, 2001, Kinzurik et al. 2016). Several studies where the treatments that have been applied were expected to modify the redox potential during fermentation have shown changes in VSC formation. These include YAN supplementation (Vos and Gray 1979, Jiranek et al. 1995, Rauhut et al. 1999, Ugliano et al. 2009, 2011, Nowak et al. 2013, Kraft et al. 2023), ascorbic or glutathione additions (Rauhut et al. 2001), or aeration at points during fermentation (Bekker et al. 2016, Day et al. 2021), which have all shown modification of VSC formation, but the redox potentials and profiles in those experiments were neither measured nor controlled. Future studies with controlled redox potentials during such fermentations might provide further insights into VSC formation.

Studies of redox potential during wine fermentation are not new. An early review of the interest in redox potential during beer and wine fermentations notes that earlier researchers had proposed that the redox potential within yeast cells was in an equilibrium with the redox potential of their surroundings (Graff 1950). The decline in the redox potential to a minimum during active yeast growth was also known at that time (Schanderl 1948, Graff 1950). This pattern and its slow recovery are also described in later wine fermentation studies (Joslyn 1949, Schanderl 1959). Redox potential can be controlled during wine fermentation by the addition of air, as previously demonstrated (Killeen et al. 2018), and its application to a commercial fermentation across a 100-fold volume has been reported for a red wine fermentation (Nelson et al. 2023). We are aware of full-scale implementations of controlled redox potentials in a limited number of commercial red and white wine fermentations during the 2024 harvests in New Zealand and California (Nelson et al. 2025).

This study focused on the effect of a single setpoint condition of the redox potential during a fermentation condition on H2S formation only. Future studies might consider the effect of other setpoint values and alternative control strategies on the formation of other impact aroma components such as VSCs and sulfite formation (leading to acetaldehyde trapping), and the levels of higher alcohols, esters, and other volatiles, even in the absence of elemental sulfur.

Previous studies have shown that yeast strains differ in the extent of H2S formation (Schanderl 1959, Rankine 1963, Acree et al. 1972, Thomas et al. 1993, Rauhut et al. 1999, Park et al. 2000) and these outcomes might be determined in part, or in total, by the solution potentials reached during each fermentation. There should be a focus on the redox potential curves that are developed by different strains, the role of nutrient composition on the ability of different strains to modify redox potential, and the role of juice composition in determining the response in the redox potential due to the changes associated with yeast metabolism or introduced by control actions.

The redox potential of a juice is initially established by the equilibrium between iron-tartrate complexes in the (II) and (III) states, and it is the concentration of the Fe(II)-tartrate complex that iron will determine the concentration of O2 that can be activated at any time. The need for the iron to be in this form to react with O2 and form H2O2 has long been known (Ribéreau-Gayon 1933). The autoxidation of tartaric acid and the role of its Fe(II)-tartrate complexes in O2 activation, and the mechanism for the development of H2O2 at wine pH conditions has been established and quantified (Coleman et al. 2020, 2022). It is the activation of dissolved O2 by the Fe(II)-tartrate complex that results in the formation of H2O2 and its concentration and reactions that are responsible for the rise in redox potential, usually within 10 to 20 min. The responsiveness of the redox potential to air additions is thought to be determined by the oxidized and reduced forms of the iron, copper, and glutathione composition of the juice. The rate at which the redox potential changes can be limited by the delivery of low concentrations of dissolved O2. A review of the application of the control of the redox potential during research and commercial fermentations provides more examples (Nelson et al. 2025).

Juice concentrations of the total glutathione in several cultivars ranged from 42 to 333 uM (12.9 to 102 mg/L) (Cheynier et al. 1989), but this survey needs to be extended and updated for a wider range of cultivars and viticultural practices. The total sulfhydryl value in the juice in the present study was 252.4 mg/L (827 uM), as reduced glutathione. Knowledge of the reduced glutathione concentration in juices is essential if improved culture media are to be developed for reproducible studies of yeast metabolism that are likely to be redox-related in wine-like fermentations. The formation of glutathione (as well as H2S) during wine fermentation has been reported (Park et al. 2000), and it varied significantly during fermentation because of yeast strain and cultivar used. Further studies of glutathione formation by wine yeast strains, in a wider range of juices and redox conditions, would contribute toward a quantitative model for O2 consumption, H2O2 formation, and the ability to control redox potential during fermentation by air or O2 additions. These studies might include the quantification of glutathione and H2O2 to understand the environmental response of S. cerevisiae during fermentation.

The secondary outcome of this trial is the faster completion of fermentation due to the application of a controlled redox potential. One cause of slow or sluggish fermentation is a deficiency in YAN (Bisson and Butzke 2000). This juice had both high YAN (in inorganic and organic forms) and a yeast formulation that was rich in vitamins and survival factors that claims to prevent incomplete fermentation when added. It appears from this replicated trial that the controlled redox potential had a metabolic effect of completing the fermentation 2 days earlier even when commercially accepted levels of YAN, vitamins, and survival factors were present. Parameter estimation of the density curves using a fermentation model (Nelson and Boulton 2024) indicates that the primary effect of the controlled redox potential was on the specific maintenance rate of the nongrowing cells, 0.25 versus 0.14 gm sugar/gm cell mass/hr. This agrees with earlier reports of similar effects on maintenance rate and cell viability (Killeen et al. 2018).

One important aspect of maintaining a controlled redox potential during wine fermentation is the reproducibility of the outcomes. This is especially true for the use of defined media, which do not include tartaric acid and/or reduced glutathione for yeast evaluations, and in studies of sluggish and incomplete fermentations. Reproducibility will also be a factor in fermentation treatments involving the addition of O2 in research trials, and in winemaking practices that introduce O2 additions but which have rarely quantified the redox environment. As a medium property that can influence fermentation rates and final chemistries, it might be considered as a requirement in future fermentation research that redox potential values are measured and reported, as it is for other fermentation environmental properties such as temperature and pH.

This study provides the first reproducible demonstration of limiting H2S formation when elemental sulfur is present during wine fermentation. It also confirms redox potential as a medium property that influences yeast activity and fermentation performance.

Conclusion

This study demonstrates that H2S formation during fermentation in which elemental sulfur is present can be limited by application of a controlled redox potential. It also confirms that fermentation under a controlled redox potential goes to completion earlier than that in which there is no such control. There is a significantly higher concentration of glutathione in the wines, for which the redox potential was controlled.

Data Availability

All data underlying this study are included in the article.

Footnotes

  • This work was supported by Jackson Family Wines. The authors acknowledge the contributions of Jeffrey Jensen with the controlled redox system.

  • Young S, Merrell C, Arvik T and Boulton R. 2025. Redox control of a Chardonnay fermentation to limit the conversion of elemental sulfur to hydrogen sulfide. Am J Enol Vitic 76:0760021. DOI: 10.5344/ajev.2025.24071

  • By downloading and/or receiving this article, you agree to the Disclaimer of Warranties and Liability. If you do not agree to the Disclaimers, do not download and/or accept this article.

  • Received December 2024.
  • Accepted May 2025.
  • Published online August 2025

This is an open access article distributed under the CC BY 4.0 license.

References

  1. ↵
    1. Acree TE,
    2. Sonoff EP and
    3. Splittstoesser DF.
    1972. Effect of yeast strain and type of sulfur on hydrogen sulfide production. Am J Enol Vitic 23:6-9. DOI: 10.5344/ajev.1972.23.1.6
    OpenUrlAbstract/FREE Full Text
  2. ↵
    1. Allison RB,
    2. Montgomery A and
    3. Sacks GL.
    2022. Analysis of free hydrogen sulfide in wines using gas detection tubes. Catalyst 6:1-8. DOI: 10.5344/catalyst.2021.21003
    OpenUrlCrossRef
  3. ↵
    1. Araujo LD,
    2. Vannevel S,
    3. Buica A,
    4. Callerot S,
    5. Fedrizzi B,
    6. Kilmartin PA et al
    . 2017. Indications of the prominent role of elemental sulfur in the formation of the varietal thiol 3-mercaptohexanol in Sauvignon blanc wine. Food Res Int 98:79-86. DOI: 10.1016/j.foodres.2016.12.023
    OpenUrlCrossRefPubMed
  4. ↵
    1. Ayer A,
    2. Sanwald J,
    3. Pillay BA,
    4. Meyer AJ,
    5. Perrone GG and
    6. Dawes IW.
    2013. Distinct redox regulation in sub-cellular compartments in response to various stress conditions in Saccharomyces cerevisiae. PLoS ONE 8:e65240. DOI: 10.1371/journal.pone.0065240
    OpenUrlCrossRefPubMed
  5. ↵
    1. Ayer A,
    2. Gourlay CW and
    3. Dawes IW.
    2014. Cellular redox homeostasis, reactive oxygen species and replicative ageing in Saccharomyces cerevisiae. FEMS Yeast Res 14:60-72. DOI: 10.1111/1567-1364.12114
    OpenUrlCrossRefPubMed
  6. ↵
    1. Beard WE and
    2. Guenzi WD.
    1983. Volatile sulfur compounds from a redox-controlled cattle-manure slurry. J Environ Qual 12:113-116. DOI: 10.2134/jeq1983.00472425001200010020x
    OpenUrlCrossRef
  7. ↵
    1. Bekker MZ,
    2. Day MP,
    3. Holt H,
    4. Wilkes E and
    5. Smith PA.
    2016. Effects of oxygen exposure during fermentation on volatile sulfur compounds in Shiraz wine and a comparison of strategies for remediation of reductive character. Aust J Grape Wine Res 22:24-35. DOI: 10.1111/ajgw.12172
    OpenUrlCrossRef
  8. ↵
    1. Bisson LF and
    2. Butzke CE.
    2000. Diagnosis and rectification of stuck and sluggish fermentations. Am J Enol Vitic 51:168-177. DOI: 10.5344/ajev.2000.51.2.168
    OpenUrlAbstract/FREE Full Text
  9. ↵
    1. Bratsch SG.
    1989. Standard electrode potentials and temperature coefficients in water at 298.15 K. J Phys Chem Ref Data 18:1-21. DOI: 10.1063/1.555839
    OpenUrlCrossRef
  10. ↵
    1. Butzke CE and
    2. Park SK.
    2011. Impact of fermentation rate changes on potential hydrogen sulfide concentrations in wine. J Microbiol Biotechnol 21:519-524. DOI: 10.4014/jmb.1010.10058
    OpenUrlCrossRefPubMed
  11. ↵
    1. Cheynier V,
    2. Souquet JM and
    3. Moutounet M.
    1989. Glutathione content and glutathione to hydroxycinnamic acid ratio in Vitis vinifera grapes and musts. Am J Enol Vitic 40:320-324. DOI: 10.5344/ajev.1989.40.4.320
    OpenUrlAbstract/FREE Full Text
  12. ↵
    1. Coleman RE,
    2. Boulton RB and
    3. Stuchebrukhov AA.
    2020. Kinetics of autoxidation of tartaric acid in presence of iron. J Chem Phys 153:064503. DOI: 10.1063/5.0013727
    OpenUrlCrossRefPubMed
  13. ↵
    1. Coleman RE,
    2. Stuchebrukhov AA and
    3. Boulton RB.
    2022. The kinetics of autoxidation in wine. In Recent Advances in Chemical Kinetics. Farrukh MA (ed.). IntechOpen, London. DOI: 10.5772/intechopen.103828
    OpenUrlCrossRef
  14. ↵
    1. Day MP,
    2. Espinase Nandorfy D,
    3. Bekker MZ,
    4. Bindon KA,
    5. Solomon M,
    6. Smith PA et al
    . 2021. Aeration of Vitis vinifera Shiraz fermentation and its effect on wine chemical composition and sensory attributes. Aust J Grape Wine Res 27:360-377. DOI: 10.1111/ajgw.12490
    OpenUrlCrossRef
  15. ↵
    1. De Graef MR,
    2. Alexeeva S,
    3. Snoep JL and
    4. Teixeira de Mattos MJ.
    1999. The steady-state internal redox state (NADH/NAD) reflects the external redox state and is correlated with catabolic adaption in Escherichia coli. J Bacteriol 181:2351-2357. DOI: 10.1128/jb.181.8.2351-2357.1999
    OpenUrlAbstract/FREE Full Text
  16. ↵
    1. Dekker S,
    2. Fedrizzi B,
    3. van Leeuwen KA,
    4. Nardin T,
    5. Dell’Anna C and
    6. Larcher R.
    2022. Time course accumulation of polysulfides in Chardonnay and model juice fermentations. Food Chem 371:131341. DOI: 10.1016/j.foodchem.2021.131341
    OpenUrlCrossRefPubMed
  17. ↵
    1. Devai I and
    2. DeLaune RD.
    1995. Formation of volatile sulfur-compounds in salt-marsh sediment as influenced by soil redox condition. Org Geochem 23:283-287. DOI: 10.1016/0146-6380(95)00024-9
    OpenUrlCrossRef
  18. ↵
    1. Graff Y.
    1950. Le potentiel d’oxydo-réduction. Application des notions d’oxydo-réduction à la brasserie et à l’oenologie. Ann Nutr Aliment 4:253-294.
    OpenUrl
  19. ↵
    1. Herszage J and
    2. Ebeler SE.
    2011. Analysis of volatile organic sulfur compounds in wine using headspace solid-phase microextraction gas chromatography with sulfur chemiluminescence detection. Am J Enol Vitic 62:1-8. DOI: 10.5344/ajev.2010.10099
    OpenUrlAbstract/FREE Full Text
  20. ↵
    1. Hjorth M,
    2. Pedersen CØ and
    3. Feilberg A.
    2012. Redox potential as a means to control the treatment of slurry to lower H2S emissions. Sensors 12:5349-5362. DOI: 10.3390/s120505349
    OpenUrlCrossRefPubMed
  21. ↵
    1. Izawa S,
    2. Inoue Y and
    3. Kimura A.
    1995. Oxidative stress response in yeast: Effect of glutathione on adaption to hydrogen peroxide in Saccharomyces cerevisiae. FEBS Lett 368:73-76. DOI: 10.1016/0014-5793(95)00603-7
    OpenUrlCrossRefPubMed
  22. ↵
    1. Janz GJ and
    2. Taniguchi H.
    1953. The silver-silver halide electrodes. Preparation, stability, and standard potentials in aqueous and nonaqueous media. Chem Rev 53:397-437. DOI: 10.1021/cr60166a002
    OpenUrlCrossRef
  23. ↵
    1. Jastrzembski JA,
    2. Allison RB,
    3. Friedberg E and
    4. Sacks GL.
    2017. Role of elemental sulfur in forming latent precursors of H2S in wine. J Agric Food Chem 65:10542-10549. DOI: 10.1021/acs.jafc.7b04015
    OpenUrlCrossRef
  24. ↵
    1. Jiranek V,
    2. Langridge P and
    3. Henschke PA.
    1995. Regulation of hydrogen sulfide liberation in wine-producing Saccharomyces cerevisiae strains by assimilable nitrogen. Appl Environ Microbiol 61:461-467. DOI: 10.1128/aem.61.2.461-467.1995
    OpenUrlAbstract/FREE Full Text
  25. ↵
    1. Joslyn MA.
    1949. Oxidation-reduction potentials at various stages of production and aging. Ind Eng Chem 41:587-592. DOI: 10.1021/ie50471a031
    OpenUrlCrossRef
  26. ↵
    1. Killeen DJ,
    2. Boulton RB and
    3. Knoesen A.
    2018. Advanced monitoring and control of redox potential in wine fermentation. Am J Enol Vitic 69:394-399. DOI: 10.5344/ajev.2018.17063
    OpenUrlAbstract/FREE Full Text
  27. ↵
    1. Kinzurik MI,
    2. Herbst-Johnstone M,
    3. Gardner RC and
    4. Fedrizzi B.
    2016. Hydrogen sulfide production during yeast fermentation causes the accumulation of ethanethiol, S-ethyl thioacetate and diethyl disulfide. Food Chem 209:341-347. DOI: 10.1016/j.foodchem.2016.04.094
    OpenUrlCrossRef
  28. ↵
    1. Kontogeorgos N and
    2. Roussis IG.
    2014. Total free sulphydryls of several white and red wines. S Afr J Enol Vitic 35:125-127. DOI: 10.21548/35-1-991
    OpenUrlCrossRef
  29. ↵
    1. Kraft D,
    2. Zhou Q,
    3. Qian M and
    4. Osborne J.
    2023. Impact of nitrogen and elemental sulfur on formation of volatile sulfur compounds during fermentation of Pinot noir grapes. Fermentation 9:904. DOI: 10.3390/fermentation9100904
    OpenUrlCrossRef
  30. ↵
    1. Kumar GR,
    2. Ramakrishnan V and
    3. Bisson LF.
    2010. Survey of hydrogen sulfide production in wine strains of Saccharomyces cerevisiae. Am J Enol Vitic 61:365-371. DOI: 10.5344/ajev.2010.61.3.365
    OpenUrlAbstract/FREE Full Text
  31. ↵
    1. Kwasniewski MT,
    2. Sacks GL and
    3. Wilcox WF.
    2014. Persistence of elemental sulfur spray residue on grapes during ripening and vinification. Am J Enol Vitic 65:453-462. DOI: 10.5344/ajev.2014.14027
    OpenUrlAbstract/FREE Full Text
  32. ↵
    1. Müller N and
    2. Rauhut D.
    2018. Recent developments on the origin and nature of reductive sulfurous off-odours in wine. Fermentation 4:62. DOI: 10.3390/fermentation4030062
    OpenUrlCrossRef
  33. ↵
    1. Nelson J and
    2. Boulton R.
    2024. Models for wine fermentation and their suitability for commercial applications. Fermentation 10:269. DOI: 10.3390/fermentation10060269
    OpenUrlCrossRef
  34. ↵
    1. Nelson J,
    2. Coleman R,
    3. Chacon-Rodriguez L,
    4. Runnebaum R,
    5. Boulton RB and
    6. Knoesen A.
    2023. Advanced monitoring and control of redox potential in wine fermentation across scales. Fermentation 9:7. DOI: 10.3390/fermentation9010007
    OpenUrlCrossRef
  35. ↵
    1. Nelson J,
    2. Boulton RB and
    3. Knoesen A.
    2025. Redox potential and its control in research and commercial wine fermentations. Fermentation 11:9. DOI: 10.3390/fermentation11010009
    OpenUrlCrossRef
  36. ↵
    1. Nessler J.
    1885. Die Bereitung, Pflege und Untersuchung des Weines. Verlag Eugen Ulmer, Stuttgart, Germany.
  37. ↵
    1. Nowak A,
    2. Koch-Wilk M and
    3. Pogorzelski E.
    2013. Effect of nitrogen sources on fermentation process and formation of hydrogen sulfide and ethyl carbamate by wine yeast. Biotechnol Food Sci 77:11-23. DOI: 10.34658/bfs.2013.77.1.11-23
    OpenUrlCrossRef
  38. ↵
    1. Park S-K.
    2001. Sulfide problems and practical solutions. Am Vineyard 10:38, 40-42, 44-46, 48, 50, and 52.
    OpenUrl
  39. ↵
    1. Park S-K.
    2008. Development of a method to measure hydrogen sulfide in wine fermentation. J Microbiol Biotechnol 18:1550-1554.
    OpenUrlPubMed
  40. ↵
    1. Park S-K,
    2. Boulton RB and
    3. Noble AC.
    2000. Formation of hydrogen sulfide and glutathione during fermentation of white grape musts. Am J Enol Vitic 51:91-97. DOI: 10.5344/ajev.2000.51.2.91
    OpenUrlAbstract/FREE Full Text
  41. ↵
    1. Perrone GG,
    2. Grant CM and
    3. Dawes IW.
    2005. Genetic and environmental factors influencing glutathione homeostasis in Saccharomyces cerevisiae. Mol Bio Cell 16:218-230. DOI: 10.1091/mbc.E04-07-0560
    OpenUrlCrossRefPubMed
  42. ↵
    1. Pourbaix M.
    1974. Atlas of Electrochemical Equilibria in Aqueous Solutions. 2d ed. National Association of Corrosion Engineers.
  43. ↵
    1. Rankine BC.
    1963. Nature, origin and prevention of hydrogen sulphide aroma in wines. J Sci Food Agric 14:79-91. DOI: 10.1002/jsfa.2740140204
    OpenUrlCrossRef
  44. ↵
    1. Rauhut D and
    2. Kürbel H.
    1994. The production of H2S from elemental sulfur residues during fermentation and its influence on the formation of sulfur metabolites causing off-flavors in wines. Wein-Wissenschaft 49:27-36.
    OpenUrl
  45. ↵
    1. Rauhut D,
    2. Kürbel H,
    3. Ellwanger S,
    4. Löhnertz O and
    5. Grossmann M.
    1999. Influence of yeast strain, assimilable nitrogen, fermentation temperature and sulfur residues on the occurrence of volatile sulfur compounds during and after fermentation. In Proceedings, Oenologie 99: 6e Symposium International d’Oenologie. pp. 305-308. Bordeaux, France.
  46. ↵
    1. Rauhut D,
    2. Shefford PG,
    3. Roll C,
    4. Kürbel H,
    5. Pour Nikfardjam MS,
    6. Loos U et al
    . 2001. Effect of pre- and/or post-fermentation addition of antioxidants like ascorbic acid or glutathione on fermentation, formation of volatile sulfur compounds and other substances causing off-flavours in wine. In Proceedings of the 26th World Congress of Vine and Wine. pp. 76-82. OIV, Adelaide, Australia.
  47. ↵
    1. Ribéreau-Gayon J.
    1933. Contribution à l’étude des oxydations et réductions dans les vins. Application à l’etude de vieillissement et des cases. Thèse Doctorat ès Sciences Physiques: Institute d’Oenologie, University of Bordeaux, France.
  48. ↵
    1. Riondet C,
    2. Cachon R,
    3. Wache Y,
    4. Alcaraz G and
    5. Divies C.
    2000. Extracellular oxidoreduction potential modifies carbon and electron flow in Escherichia coli. J Bacteriol 182:620-626. DOI: 10.1128/jb.182.3.620-626.2000
    OpenUrlAbstract/FREE Full Text
  49. ↵
    1. Sarmadi B,
    2. Kilmartin PA,
    3. Araújo LD and
    4. Bastow BP.
    2024. Analyzing the role of elemental sulfur in grape juice on the development of polyfunctional mercaptans in Sauvignon blanc wines. In IVES Conference Series, OENO Macrowine 2023. International Viticulture and Enology Society, Bordeaux, France.
  50. ↵
    1. Schanderl H.
    1948. Die reduktions-oxydations-potentiale wahrend der entwicklungsphasen des weines. Wein Wiss Beih Zeit 7:191-198, 209-229.
    OpenUrl
  51. ↵
    1. Schanderl H.
    1959. Mikrobiologie des Mostes und Weines. Verlag Eugen Ulmer, Stuttgart, Germany.
  52. ↵
    1. Schutz M and
    2. Kunkee RE.
    1977. Formation of hydrogen sulfide from elemental sulfur during fermentation by wine yeast. Am J Enol Vitic 28:137-144. DOI: 10.5344/ajev.1977.28.3.137
    OpenUrlAbstract/FREE Full Text
  53. ↵
    1. Smith ME,
    2. Bekker MZ,
    3. Smith PA and
    4. Wilkes EN.
    2015. Sources of volatile sulfur compounds in wine. Aust J Grape Wine Res 21:705-712. DOI: 10.1111/ajgw.12193
    OpenUrlCrossRef
  54. ↵
    1. Stratford M and
    2. Rose AH.
    1985. Hydrogen sulphide production from sulphite by Saccharomyces cerevisiae. J Gen Microbiol 131:1417-1424. DOI: 10.1099/00221287-131-6-1417
    OpenUrlCrossRef
  55. ↵
    1. Thomas CS,
    2. Boulton RB,
    3. Silacci MW and
    4. Gubler WD.
    1993. The effect of elemental sulfur, yeast strain, and fermentation medium on hydrogen sulfide production during fermentation. Am J Enol Vitic 44:211-216. DOI: 10.5344/ajev.1993.44.2.211
    OpenUrlAbstract/FREE Full Text
  56. ↵
    1. Ugliano M,
    2. Fedrizzi B,
    3. Siebert T,
    4. Travis B,
    5. Magno F,
    6. Versini G et al
    . 2009. Effect of nitrogen supplementation and Saccharomyces species on hydrogen sulfide and other volatile sulfur compounds in Shiraz fermentation and wine. J Agric Food Chem 57:4948-4955. DOI: 10.1021/jf8037693
    OpenUrlCrossRefPubMed
  57. ↵
    1. Ugliano M,
    2. Kolouchova R and
    3. Henschke PA.
    2011. Occurrence of hydrogen sulfide in wine and in fermentation: Influence of yeast strain and supplimentation of yeast nitrogen. J Ind Microbiol Biotechnol 38:423-429. DOI: 10.1007/s10295-010-0786-6
    OpenUrlCrossRefPubMed
  58. ↵
    1. Vos PJA and
    2. Gray RS.
    1979. The origin and control of hydrogen sulfide during fermentation of grape must. Am J Enol Vitic 30:187-197. DOI: 10.5344/ajev.1979.30.187
    OpenUrlAbstract/FREE Full Text
  59. ↵
    1. Widmer A.
    1936. Die verwendung des elektrokatadynapparates zur unterscheidung der verschiedenen arten von bockser bei wein und obstwein und in der laboratoriumspraxis. Mitt Geb Lebens Hyg Bern 27:352-356.
    OpenUrl
Back to top
Print
View full PDF
Email Article
Citation Tools

Open Access
Redox Control of a Chardonnay Fermentation to Limit the Conversion of Elemental Sulfur to Hydrogen Sulfide
Samantha Young, Caroline Merrell, Torey Arvik, Roger Boulton
Am J Enol Vitic.  2025  76: 0760021  ; DOI: 10.5344/ajev.2025.24071
del.icio.us logo Twitter logo Facebook logo Mendeley logo
Save to my folders

Jump to section