Sulfur smell, Lalvin 71b

[PhreneticMoon]

Hi,

I'm getting sulfur smells in my mead. Details below.

6 gallon batch, 18 lbs Wildflower honey (Kirkland), 4.5 gallons water, pre-boiled and cooled, campden added.
12 grams Lalvin 71b rehydrated per Scott Labs' protocol (15 grams goferm, attemperated to meet must temps).
Pitched at 67f nearly 48 hours ago after oxygenating for 2.5 minutes with stone and pure oxygen. I use a stainless conical with temp control (all SSBrewtech), so temp differential is 1 degree of 67.
Good airlock activity within 12 hours of pitch.
Aerated must 24 hours later with drill and stirring bit, then added first nutrient addition (5.6 grams Fermaid O mixed in 1 liter of must until visibly dissolved, then added back to fermenter). Smelled fine, still good airlock activity.
Today, checked on my beasties, strong sulfuric smell. I have at least 3 hours until my nutrients are scheduled.

This is the second time this has happened with the exact recipe and protocols. After adding second dose of nutrient, smell dissipated and didn't return.

Questions: is Lalvin 71b prone to sulfuric smell early in fermentation? Could sulfur smell be caused by things other than yeast stress? Do TOSNA addition schedule need to be adjusted based on each fermentation, even if all controllable factors are the same each time?

 

[EricHartman]

Sulfur smells are not only associated with stressed yeast but they can be caused by them. Not sure if you've ever made a cyser but you definitely have a nice period of apple farts in the basement for around 48h. If everything else is going fine I'm not sure I'd fret about the situation. Especially if the last batch turned out ok. In that batch the smell may have gone away due to the nutrient, or due to the aeration prior to the nutrient addition. I don't always strictly follow the TOSNA schedule. I'll commonly put the first 2 in fairly close together as the yeast sure seem to like fermenting to the 1/3 sugar break rather quickly.

 

[PhreneticMoon]

Thanks, Eric!
Yep, smell gone today as though it was never there. Next batch, I'm going to check morning after 1st nutrient addition, and if there's a smell, I'll probably just aerate and add nutrients early.

 

[MightyMosin]

This is a timely post. I just got back from a 2 week vacation and before I left I had a short mead that had finished fermenting before I left. I added 2 crushed campden tablets to it for stabilization and went away. I

I get back and open the airlock to sample it and get hit with a strong sulphur smell. I added the campden before leaving so that bacteria would be inhibited as it is a low alcohol mead.

I'm going to leave it with an empty airlock tonight and see how well it clears out and smell before I empty it out.

 

[edaskew]

Most likely that sulfur aroma will dissipate over time. Don’t bottle the mead until it does. 71b is prone to skunky smells. If you want to avoid that in the future use k1v or QA23.

 

[MightyMosin]

Most likely that sulfur aroma will dissipate over time. Don’t bottle the mead until it does. 71b is prone to skunky smells. If you want to avoid that in the future use k1v or QA23.

This mead is using the Mangrove Jack Mead yeast. It is my first time using it, so I have no reference on how it reacts/acts. It's a yeast that is capable of high alcohol %, but I didn't use it for that purpose. Maybe its just a case of the yeast being stressed as they are out of food.

Will check on it later, but I have emptied the airlock so that the smell has a chance to dissipate into the air.

 

[edaskew]

if the mead is done with fermentation, and the airlock is empty,it’s exposed to oxygen and that’s definitely not desirable. I’m afraid patience is in order. You need to refil the airlock and give it time.

 

[MightyMosin]

if the mead is done with fermentation, and the airlock is empty,it’s exposed to oxygen and that’s definitely not desirable. I’m afraid patience is in order. You need to refil the airlock and give it time.

I'll rack it tomorrow and see if the smell is still there after a few hours.

 

[MightyMosin]

I'm assuming if the bad smells continue after a week or so that the batch is just trash.

It's a low ABV and is done with primary fermentation.

 

[edaskew]

Not necessarily. Just allow it to sit for a while. I have had some of those skunky smells in meads I thought would become dumpbrau, but ended up being very good. Campden tablets are not the way to stabilize mead. I don't know if you did that before the mead was finished, but if you did, that's not a good idea either. Whatever, I wouldn't dump the mead. Give it time.

 

[edaskew]

Plus I just want to say this: mead making is about patience. Slow down, take your time. Mead takes time. Reading your post I can see you are too impatient. This idea of making mead in a month; that's a waste of labor and money.

 

[MightyMosin]

Not necessarily. Just allow it to sit for a while. I have had some of those skunky smells in meads I thought would become dumpbrau, but ended up being very good. Campden tablets are not the way to stabilize mead. I don't know if you did that before the mead was finished, but if you did, that's not a good idea either. Whatever, I wouldn't dump the mead. Give it time.

This one is approx 5% and I thought that the campden helps keep bacteria in check.

 

[edaskew]

Yeah. It will. It will also protect against oxidation. I think most of us stabilize with K meta, and you make a calculation based on pH, volume, and free SO2 level. You have to wait until the mead is finished with fermentation, and usually after a cold crash. If you hit it just right, you stabilize the mead and you can't taste the sulfites. Maybe what you're smelling and tasting is too much sulfites, but that will dissipate over time. I did that with one of my meads and over several months it went away. We also add potassium sorbate when stabilizing. I add 1/3 tsp per gallon, which is a low dose, but my meads are over 12% alcohol.

 

[EricHartman]

This one is approx 5% and I thought that the campden helps keep bacteria in check.

That's approaching a conceringly low abv. I think 4.6% is a cutoff where a good number of bacteria thunder in... and in particular the vegetative (active) form of botulinum (botulism). It's spore will survive quite a bit of alcohol but it's the toxins produced by the active ones that are problematic... for adults anyway... and if your newborn is drinking mead quit wasting it! Darn kid can't appreciate it properly. You'll be relying on your sulfites alone to keep the baddies away, which is certainly fine, but a step closer to trouble

 

[edaskew]

The pH is probably too low for botulinum. I would worry if it's over 4.0, but it's probably not. 4.5 or 4.6 is supposed to be the cutoff, but I wouldn't cut it that close.

 

[EricHartman]

Oh fair enough. I didn't consider the pH; most of mine land early to low 3s though I've never made a mead with so little active fermentation phase.

 

[MightyMosin]

This is a good set of comments. I've never tried a low %abv mead and I am just kind of flying by the seat of my pants.

Any suggestions on where I should read regarding the pH and alcohol levels that can be problematic?

 

[EricHartman]

If you look up "shelf stable standards" you should get some very good data on what makes something safe to eat over time. pH, alcohol, salt content, water content, and then chemical preservatives are all contributing factors. A couple of years ago I wondered if you could get botulism from mead, given that the spores can be in honey, so I went down a rabbit hole lol. Found a paper on a guy who poisoned himself and a few other inmates making puna (prison booze) with botulism... so theoretically it's possible. His protocols were considerably less vigorous than ours tend to be and ultimately it seemed like you'd have to try fairly hard to hurt yourself in this way. Clearly my brain likes to worry about it though lol

 

[Dan O]

If you look up "shelf stable standards" you should get some very good data on what makes something safe to eat over time. pH, alcohol, salt content, water content, and then chemical preservatives are all contributing factors. A couple of years ago I wondered if you could get botulism from mead, given that the spores can be in honey, so I went down a rabbit hole lol. Found a paper on a guy who poisoned himself and a few other inmates making puna (prison booze) with botulism... so theoretically it's possible. His protocols were considerably less vigorous than ours tend to be and ultimately it seemed like you'd have to try fairly hard to hurt yourself in this way. Clearly my brain likes to worry about it though lol

I can't imagine very sanitary conditions in prison though, hence, the botulism

 

[EricHartman]

Lol yeah the fermentation was done on a potato liberated from the cafeteria, peeled by fingernails, and fermented in a zip lock bag. Clearly he needed to spend some time on gotmead.