SagamoreAle

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I am making a raspberry melomel and ran into a sulphur (rotten egg) smell about 1 day into fermentation.

I'm using Pasteur Champage Yeast. OG was 55. (I'm planning on stepping this up to an effective OG of around 120).

When I discovered the problem, I added plenty of yeast nutrient and yeast energizer, and aerated with an aquarium pump for about 90 minutes. I also used a wort aerator (the kind that attaches to your electric drill) to degass, which successfully drove out a lot of SO2 based upon the stink it raised. I also added shiny copper pennies.

One day later, I still have plenty of SO2 odor. I've just reduced fermentation temperature from 68 to 63, measured by a thermometer in direct contact with the fermenting mead.

Any ideas about how to treat this further, assuming the temperature adjustment doesn't solve the problem?

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Ex fermentum, scientia.

JustinCider

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Time......

saramc

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Are you in a bucket or carboy? May want to try splash racking into a new primary, splashing over the copper.

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Motto: quel che sara sara

VCTFernandes

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Won't the copper pennies cause even more sulphur odor? I read somewhere that this trick should only be used if there was no fermentation going on, otherwise it would cause problems... (I may be wrong, let's wait for someone more experienced)

Bluespark

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Just leave it for a bit. I had a mead that smelled awful, I left it and it fixed itself. I'm thinking with mead time fixes the majority of things.

SagamoreAle

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Well the mead has reached 63F at this point. Fermentation has (obviously) slowed, along with SO2 production. The question is, has the SO2 production proportionately dropped because of the lower temperature, or has it really stopped (or at least down to a normal level). I degassed again with the wort aerator and stank up the whole room. The mead of course tastes like sulfur. I'm optimistic the rest of it will scrub out with the CO2.

Fortunately I've only used just over 1/3 of my honey and fruit. So if this batched is permanently damaged I can retry and keep the initial fermentation temperature low.

What I'll probably do is wait a couple of days and see if the sulfur odor and taste continues to drop due to the reduced fermentation temperature. If so, I'll splash-rack onto copper and additional fermentables. If not, I'll start a start a parallel melomel with a lower initial fermentation temperature. I guess worst-case-scenario I have an oportunity to do some controlled experiments.

Hopefully aging will drive out the remainder of the odor and taste. If I add more fruit, there is even more opportunity for CO2 scrubbing. I just want to make sure I'm on the right track. 15# of honey and 10# of raspberries is not cheap.

__________________
Ex fermentum, scientia.

saramc

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It should go away...you are on the right track.

__________________
Motto: quel che sara sara

SagamoreAle

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I found this quote festering in several descriptions of Pasteur Champagne Yeast. I hope I'm not having a learning experience. I've been making mead for too long to run into this kind of problem:

I hope this doesn't apply to my raspberries. I'm going to assume it does, and change my go-forward plan as follows:

- reduce fermentation temp to 55F
- get the rest of the raspberries in at one time
- degas nightly if I detect any sulfur taste or smell
- add the rest of the honey when raspberry fermentation is complete. Hopefully the CO2 from the honey fermentation will scrub out the remaining H2S

__________________
Ex fermentum, scientia.

SagamoreAle

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Reducing the fermentation temperature didn't help. Still a sulfur odor and taste. I went back up to 64F because there was too little action below 60.

My trusty 10-year-old pH meter had bit the dust and I decided to invest in a new one. pH was 2.8 and TA was .9%. Perhaps this was my smoking gun. I adjusted (with calcium carbonate) to pH of 3.4 and TA of .6%. I was looking for some overshoot because I was planning to step up with additional raspberries which will reduce the pH, hopefully to around 3.2.

(Fortunately I had some Calcium Carbonate for when I brew London Ales. I'll be investing in some Potassium bicarb)

The next day I added the additional raspberries and honey. The fermenters exploded out the blowoff tubes in about an hour. After cleaning the brewery, I reduced fermentation temperature by 2F on a temporary basis and replaced the 3/8 blowtubes with 1/2 (I hate blowoffs. They just waste good wine and beer).

Today, so far no sulfur smells. I'll be keeping an eye on things.

__________________
Ex fermentum, scientia.

SagamoreAle

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The sulfur smell returned. It didn't dissipate or decline after a week of waiting after fermentation completed. I ended up treating with copper sulfate. Cleaned it right up.

I used a copper sulfate bench test kit to determine the minimum amount of copper sulfate to add: http://morewinepro.com/view_product/6541//Copper_Sulfate_Bench_Trial_Kit

(not affiliated, etc.)

__________________
Ex fermentum, scientia.