ArticleStench of Sulfur & Excess CO2: Wine WizardWritten by Alison CroweQHere’s one problem you may have been asked about before. My finished wine has an aroma and taste of rubber and burnt toast, a bit like burnt rubber. Since I will be making more wine this year, I sure would like to know what I’m doing wrong. Would you let me know? Richard LarocqueL’Orignal, Ontario AI can think of two possible causes of these flavors and smells. The first is over-oaking of your wine with highly toasted chips. If you are using chips, run bench trials to see what level of oakiness you like. Take small samples of your wine and add oak chips at varying rates. Taste the wine and see what level you best enjoy. If this is too involved, play it safe and go with a low rate like 1 g/L. The second possible cause is hydrogen disulfide or mercaptans. There are numerous potential pathways for these stinky compounds to get into your wine. Sulfur spraying in the vineyard too close to the harvest date is one possibility. Yeast spit out elemental sulfur in the form ofAlready a member? Log InYou'll Also Like Article MEMBERS ONLY Bracing Barrels & Coffee Wine The level of caffeine, of course, will depend on how much coffee you used in the recipe — just as your average cup of joe will be stronger with the more ground coffee, so will your wine. Article MEMBERS ONLY Acidity & Aging My situation is that the total acidity (TA) rises during the aging process.What could be causing this?