BrewChoPs wrote:What temperature were you fermenting? How long did it stay on the yeast? How much DAP & nutrient did you have in the must? When did you notice the H2S gas?
Without getting into the full biochem discussion, you have a higher risk of forming H2S gas in the cider from these:
~ Yeast nutrient deficiency (Nitrogen, Pantothenate, Oxygen) = yeast produces more sulphide than it needs which forms as H2S gas - look at the Fermaid K and DAP additions (staggered similar to mead)
~ Too much Nitrogen (yeast metabolizes too fast- stagger nutrient additions, don't chuck it all in at the beginning
~ Wild yeast contamination
~ Higher fermentation temperatures (yeast stress)- look into cooler fermentation temps 59F to 64F
~ too much free SO2 in the must - test your must, the SO2 level needs to be less than 80mg/litre = limit your campden tablets to 1 per gallon (prefermentation) or 2.5 grams per gallon
~ Yeast autolysis - left on the lees too long (more than 2 days is pushing it)
~ when the must is 2-3 degrees Plato from being finished stir up the lees - this will help avoid redox at the bottom and control H2S production
NOW that the H2S is in your cider, CO2 flush as the others have stated. A Potassium Caseinate fining can be used. Also activated carbon filter.
Thank you. I staggered nutrients. fermentation temperature stay between 62 and 72. I transferred of the yeast appropriately when fermentation was finished. I didn't get a chance to rose the yeast before the end of fermentation.
hey homebrew shop owner told me to add mallable copper to a sample of wort to see if the sulfate would bind with the copper and drop out. The test worked. So I sanitized an inch piece of metal copper and dropped it in my keg last night. according to this home brew shop owner I should leave it in there for a few days let everything settle and transfer of the yeast, stabilize and back sweeten.