Advice on a possible slow ferment with sulfur smell.

[Vodka Drunkenski]

Hey all.
So I started a 24L batch of ginger beer on New Years eve.
Boiled 1Kg ginger with 3Kg light DME in around 10L of distilled water.
Added a couple grams Hersbruker hops for a slight bittering along with
some lime zest. Also added enough brown sugar to make a SG of 1.055,
and around 1.5 cups frozen lime juice.

Once the boil was finished I poured the wort into my SS still boiler that I'm
using for a primary. Added more distilled water to make 20L, and stirred
the living hell out of it to aerate the wort (which I assume has little
to no oxygen in it). Once the temp dropped to about 70F I pitched 4L of a
Voss Kveik starter that I had going 2 days beforehand. Capped it off with a
plastic cover that allows for CO2 to escape.

The problem is that the ferment never really kicked off as good as I expected
(although it certainly was fermenting), and now after 6 days I notice a sulfur
smell starting to take over.

So I figured I would rack it into a carboy, take a gravity reading, as well as a pH
reading (I was unable to take one at the beginning), and perhaps get a bit of
oxygen into it....just in case that's what was stressing the yeast.

The gravity after 6 days @ 68F is only at 1.030, AND the pH is at 3.8.
After racking there's a good amount of airlock activity...so adding O2
seemed to help.....BUT what about the pH? Is this also contributing to
the sulfur smell? Should I try bumping up the pH....and how should I
go about doing it?

What would you guys do?

Thanks.

 

[Zambi]

First question: how did you measure SG?
If you used a refractometer, did you correct for the presence of alcohol?

2nd: 70 F is low for kveik Voss.
It likes it warm to hot and has no issues with 100 oF

So, I would put another SG sample, then put it warmer and check again after 2-3 days.

Don't worry too much about the sulfur smell

 

[Brew Cat]

the sulfur is gassing off. It's what you want. From the ginger i'd presume. Racking will help it some if it really bothers you. If you get it in the keg, purge the CO2 every couple days and it clears. Get that with cider sometimes with certain yeast. I don't use the Kveik yeast so cant speak to that

 

[Vodka Drunkenski]

First question: how did you measure SG?
If you used a refractometer, did you correct for the presence of alcohol?

2nd: 70 F is low for kveik Voss.
It likes it warm to hot and has no issues with 100 oF

So, I would put another SG sample, then put it warmer and check again after 2-3 days.

Don't worry too much about the sulfur smell

I used a hydrometer to measure the SG. I'm pretty confident with the readings.

Unfortunately room temp is the best I can do right now...I was hoping that the
lower temp would help with a cleaner fermentation, and I was expecting a little
longer time, but coupled with the sulfur scent I started to worry that it might
be a little "stressed". It seems to be chugging along pretty good this morning
though...lots of airlock activity, so I'm thinking I didn't aerate the wort enough.
My next attempt will be an all-grain...so I won't be using distilled water.

Thanks Zambezi.

 

[Vodka Drunkenski]

the sulfur is gassing off. It's what you want. From the ginger i'd presume. Racking will help it some if it really bothers you. If you get it in the keg, purge the CO2 every couple days and it clears. Get that with cider sometimes with certain yeast. I don't use the Kveik yeast so cant speak to that

Hi Brew Cat.

I hope it's the ginger, and not yeast stress.

It's fermenting nicely this morning, so the aeration from racking did it some good.
Also, I'm a bit relieved that it "probably" isn't the low pH. I'll have to monitor the
airlock activity, and watch for any sudden changes as well as monitor the scent.

Cheers!

 

[Josh Hughes]

Don’t worry it’s off gassing and some yeast will produce sulfur smells. It’s normal for many yeasts. And PH or distilled water didn’t have anything to do with it.

 

[Vodka Drunkenski]

Don’t worry it’s off gassing and some yeast will produce sulfur smells. It’s normal for many yeasts. And PH or distilled water didn’t have anything to do with it.

Thanks Josh. I'm happy fermentation picked up after racking...I think I'll be OK. A small sample from last night actually tasted pretty good, looking forward to a good brew after aging for a couple months!

Cheers!

 

[Josh Hughes]

Love your avatar!

 

[Minbari]

I'll just add, don't add O2 after fermentation has started. Best way to oxidize your beer. Yeast needs o2 at first, later on, no.

The sulfur smell will go away once you do a D rest

 

[Vodka Drunkenski]

I'll just add, don't add O2 after fermentation has started. Best way to oxidize your beer. Yeast needs o2 at first, later on, no.

The sulfur smell will go away once you do a D rest

Thanks for the reply, Minbari.
I try to keep O2 away as much as possible...the ferment only got what was from the racking. It's fermenting away like crazy after that though!