Preventing and Treating Sulfur Off-Odors in Cider
Last updated: 11/2023
Applies to: Cidermakers looking for strategies to prevent and treat sulfur off-odors in cider.
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
For high-turbidity juices
After juice is pectin-free, add fining agents like
For low-turbidity juicesEnsure yeast is rehydrated with a
GO-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 OKAY™,ICV OPALE 2.0™,IOC BE FRUITS™,SENSY™|
|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 suspensionRack 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 oxygenpickup 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 liquidMinimize dissolved oxygenpick-up
during cellar movements and packaging