Almost a year, still sulphur aroma.

[crawfman]

Last October I started a cider experiment. I gathered 5 gallons unpasteurized fresh juice from an orchard. I let this ferment naturally for a week in a 5 gal carboy and then added campden to kill off the wild stuff. I then waited a few days and added some Belgian yeast and some bottle dregs from a couple Brett'd beers. Fermentation started back up like normal. For quite a few months now it's had a sulfur like aroma that persists. I've recently splash racked it to another carboy but, what I perceive as sulphur, is still there. Any ideas what caused this and if it's salvageable?

 

[Albionwood]

I'd say your experimental results are not encouraging. Belgian yeast and Brett might be too much for cider.

Splash-racking sounds dangerous for cider, which is super-sensitive to oxidation.

All that being said - I have a cider on tap from last year's vintage that does have a sulfur aroma, yet still tastes great. Supposedly you can clear up H2S aroma with copper sulfate, but I've never tried it.

 

[LeBreton]

It's probably too late to do much about the sulfur smell, which likely started as H2S during fermentation. Over time though, that H2S reacts with the amino acids to become mercaptans. The goal of splash-racking the cider is to introduce enough oxygen to offset the reductive sulfur aromas but only works when the enzymatic reactions are still active. Once the mercaptans have been formed, they're much harder to get rid of.

In the future, consider using a little bit of nutrient if you start to develop sulfur smells during fermentation and/or rack off the lees early when storing long-term. Copper can also bind with H2S so can be used post fermentation and before storage as a preventative measure.