Preventing and Treating Sulfur Off-Odors in Cider
Last updated: 11/2023
Applies to:Â Cidermakers looking for strategies to prevent and treat sulfur off-odors in cider.Â
SULFUR OFF-ODORS
Cider can develop sulfur off-odors which are largely attributable to hydrogen sulfide (H2S). Terms used to describe sulfur-off odors include rotten egg, reduction, burnt rubber, onion, skunky, garlic, and funk.
There are several sources of sulfur-based compounds in juice which come naturally from apples or cidermaker inputs.
During fermentation, yeast require these compounds for normal cell functions (including the production of essential amino acids like cysteine and methionine). However, when yeast become stressed they can utilize these same sulfur compounds and generate off-odors.
PREVENTING SULFUR OFF-ODORS
BEST PRACTICE | EXPLAINATION | RECOMMENDATION (product, dosage, notes) |
---|---|---|
Ensure juice is 80-120 NTU or 1-2% solids before initiating fermentation | High turbidity can cause yeast stress resulting in H2S production. Low turbidity will cause yeast to struggle to stay in suspension, potentially leading to a sluggish fermentation. | For all juices Unless juice has been confirmed pectin-free, use enzymes like RAPIDASE® CLEAR EXTREME (1-4 g/hL) or a combination of SCOTTZYME® PEC5L (1-1.3 mL/hL) + SCOTTZYME® HC (5.3-7.9 mL/hL) to break down pectin For high-turbidity juices After juice is pectin-free, add fining agents like
For low-turbidity juices Ensure yeast is rehydrated with aGO-FERM PROTECT EVOLUTION orGO-FERM STEROL FLASH(30 g/hL) and add RESKUE(40 g/hL) to increase NTUs in particularly low turbidity juices |
Employ a complete fermentation nutrition plan
| Avoid yeast stress and potentially sluggish fermentations by providing essential nutrients | Click here for assistance crafting a nutrition plan (choosing nutrients, dosages, and timing of additions) |
Inoculate with a Low to No H2S Yeast strain | Some yeast strains have been selectively bred to produce no (or very little) H2S, even under stressful conditions. | ICV OKAYâ„¢,ICV OPALE 2.0â„¢,IOC BE FRUITSâ„¢,SENSYâ„¢ |
Prevent stressful conditions during fermentation | Yeast stress can lead to the production of sulfur off-odors | Manage temperature based on choice of yeast strain Mix vessel daily to keep yeast in suspension Rack off gross lees after fermentation |
TREATING SULFUR OFF-ODORS
BEST PRACTICE | EXPLANATION | RECOMMENDATION (product, dosage, notes) |
---|---|---|
Perform bench trials to determine the most suitable treatment for your cider | These products may help to remove sulfur off-odors and refresh aromas | Tannin: FT BLANC™(5-20 g/hL) Yeast Derivative Nutrient (add anytime before the end of fermentation): REDULESS™(10-30 g/hL) Fining Agent: BENTOLACT S™(20-200 g/hL) |
Minimize oxygen pickup in the cellar | Elevated oxygen can oxidize sulfur-odors and convert them to di-sulfides which are more difficult to treat | Keep headspace to a minimum (except during active fermentation) and blanket headspace with protective gases (CO2, argon, or nitrogen) to minimize oxygen contact with liquid Minimize dissolved oxygen pick-upduring cellar movements and packaging |