How to prevent sulfur odors when brewing ginger ale / ginger beer?

Question

I made my first batch of ginger beer and it was delicious—but with prominent sewer gas undertones.

This was a simple recipe and a quick ferment: ginger, water, sugar, lemon juice, and yeast fermented on the counter out of direct sunlight for 2 days until fizzy, then into the fridge. I'm using Fleischmann's Active Dry Yeast.

Based on blog posts and forums discussions, this appears to be a common problem with ginger brews. Unfortunately the discussions I've found are long on speculation and short on facts. Often people say there can be several causes, which could well be true... but it's hard to tell which are known causes and which are guesses.

How can I prevent this problem in the future, or at least make it less likely?

Answer 1

The sulfur / boiled egg odor is hydrogen sulfide, which is produced by yeast when stressed.

It happens minimally in all fermentation but is usually gassed out during vigorous fermentation which you really don't have when just using yeast to carbonate. So extra attention needs to be placed on the strain and health of the yeast.

Primary cause of noticeable sulfur is poor yeast health or a wild strain not well suited.

There are a lot of factors that contribute to yeast health all of which have been covered in detail in other answers.

If you're using wild fermentation it may take several attempts at a ginger bug before you get one that works well. I would suggest getting a ginger bug from someone that has a successful one or just buy brewers yeast.

Update: Using bakers yeast is fine for many fermentation projects. I've used rapid rise for some great ciders. Trick is to have enough healthy yeast to do the job. So basically what you want to do is make a starter with nutrients or pitch multiple packs. Because if the yeast is alowed a growth phase in the environment of a ginger ale/beer it really doesn't have the needed nutrients to multiply without stress and producing bad esters. Also if using package yeast the process should be controlled with an airlock, or you may get a wild yeast to set dominance instead.