How best to avoid volcanic mead eruptions?

[NeverDie]

I thought that by now I had enough experience that it woldn't happen, but it did. I was degassing a 5 gallon mead with a power drill in a 6.5 gallon Big Mouth Bubbler, and it triggered a volcanic mead eruption which dumped half a gallon of sticky mead must onto the floor.

I suppose I could use an anti-foam like Fermcap S, but there seems to be some debate over whether that might have adverse health effects.

Other than just taking it more slowly, are there any other good tricks for avoiding these runaway degassings?

 

[Yooper]

I thought that by now I had enough experience that it woldn't happen, but it did. I was degassing a 5 gallon mead with a power drill in a 6.5 gallon Big Mouth Bubbler, and it triggered a volcanic mead eruption which dumped half a gallon of sticky mead must onto the floor.

I suppose I could use an anti-foam like Fermcap S, but there seems to be some debate over whether that might have adverse health effects.

Other than just taking it more slowly, are there any other good tricks for avoiding these runaway degassings?

First, start VERY slowly. Stir without turning on the drill, just to get some of the gas out first. If it's not too gassy with that, a quick burst (and I mean just a flick) will usually get enough gas out to see how bad it can be. I've had some erupt quickly with a little stir, and others don't, so it really is just a matter of how much dissolved c02 is in there.

I never use a drill degasser set up in primary, though- usually just stir three times per day for the first 5 days or so, and that's not an issue.

The drill set up only comes out if I'm rushing something to bottle, so I'd say I've only done it a handful of times in 30 years. Still, I remember the way it can volcano on you and short out your drill (not to mention electrocute you) if you're not sure of what's going to happen!

If you're degassing, I assume it's in primary (with that much headspace), so you can just stir it to get the c02 out- no need to whip the heck out of it.

 

[RPh_Guy]

Fermcap is not dangerous in the slightest.

However, just be cautious with the drill and you won't have issues.

 

[Blacksmith1]

Another option is to make cider instead, then you can have volcanic cider explosions.......

 

[RPh_Guy]

Another option is to make cider instead, then you can have volcanic cider explosions.......

Do you degas your cider?

 

[Blacksmith1]

Yes, but not with a drill, and only during the first week. After that my ferments slow to the point I don't bother.

 

[NeverDie]

Interesting! Since the goal is to both de-gass and aerate, I thought everyone was using the power drill method, whereas now it seems I'm the only one.

After doing some reading up on how mentos quickly de-gasses cola, I think part of my error was putting the stir rod too low into the mead at the start of degassing. If I had put it closer to the surface, it maybe would not have created an avalanche of nucleation points.

Yes, this mead is in primary. I pitched it less than a day ago. This is so far my biggest batch ever.

 

[RPh_Guy]

FWIW I use a drill. It's a lot faster and more effective than stirring.

 

[NeverDie]

What I'm finally figuring out is that when pitching just 2g dry yeast per gallon, the must needs a lot more aeration. Otherwise, it complains by emitting divergent aromas. When I was pitching at a much higher rate, the aeration seemed perhaps unnecessary, whereas at these low pitch rates lots of aeration seems like a definite requirement. At the moment my power drill attachment is the tool of choice for that, but I may be upgrading to a pure oxygen wand soon.

Is this what others here have noticed as well?

 

[Maylar]

I've not had any funky odors with 2 gm/gal. My initial aeration is the act of stirring in the honey with a lees stirrer and drill. Then an O2 wand at 12 and 24 hrs.

 

[Blacksmith1]

Before pitching I use a wire whip attachment on my immersion blender to aerate the must. After that I stir it couple times a day. I always use a starter also, so I never pitch dry yeast into my must.

 

[NeverDie]

Before pitching I use a wire whip attachment on my immersion blender to aerate the must. After that I stir it couple times a day. I always use a starter also, so I never pitch dry yeast into my must.

For your dry yeast, do you mean rehydration with GoFerm (which I am doing), or a real starter?

What's an immersion blender?

 

[NeverDie]

I've not had any funky odors with 2 gm/gal. My initial aeration is the act of stirring in the honey with a lees stirrer and drill. Then an O2 wand at 12 and 24 hrs.

For a mead, how much O2 do you give it?

 

[Blacksmith1]

Water, must, yeast nutrient (nutrient/energizer now), and a vigorous shake every few minutes is how I do my starters.

As for the blender, I got mine from amazon, but this is the exact same one I have.
https://www.walmart.com/ip/BELLA-Ha...edirectid=15583603041998456267810090302008005

 

[Maylar]

For a mead, how much O2 do you give it?

About 30 seconds while stirring the wand around. There is a science behind it, yeast want something like 15 ppm oxygen, but without a DO meter there's no way to know what you have. I just wing it and watch the bubbles...

 

[LittleRiver]

... I thought everyone was using the power drill method, whereas now it seems I'm the only one...

I've only done one batch of mead, but I did use a power drill. I'd read of the possibility of eruption, so for my first go with the drill I put the fermenter in a wash tub I have in my shop. Sure enough, some of it erupted, but it was an easy cleanup since it was contained.

After that I learned to start with short bursts with the drill, and give it some time to settle between bursts. Doing it that way I did not have any more eruptions. After a few burst/rest cycles I would go full bore with the drill and give it a good aeration.

It got less and less eruptive as fermentation progressed, after a few days I got a feel for how it would react and no longer felt a need to put the fermenter in the wash tub.

The mead came out great, so I will be repeating this process.

 

[Blacksmith1]

I was under the impression that yeast with O2 create more yeast, and yeast without O2 create alcohol. So once my brews get going, I just try to release CO2, not add O2.

 

[NeverDie]

I was under the impression that yeast with O2 create more yeast, and yeast without O2 create alcohol. So once my brews get going, I just try to release CO2, not add O2.

I've tried that approach, and it seems to work if the yeast population density is high enough, but if it isn't, then the result seems to be unhappy yeast. I'd be curious if it's true or not, but it seems as though the yeast are able to sense their own population density. Why do I say that? Well, consider this quotation from the Fermaid K datasheet:

"In all alcohol fermentations yeast growth must occur before the anaerobic or alcohol fermentation can begin. In most wine applications, the usual inoculation rate is 25 grams per hectoliter (250 ppm or 2 pounds per 1,000 gallons) which results in an initial cell concentration of 3 to 4 million viable yeast cells per milliliter of must. Under normal conditions for virtually all types of fermentation media the cell population will increase to 100 to 150 million viable yeast cells per milliliter before growth stops and alcohol fermentation takes over." [emphasis added by me]​

https://catalogapp.lallemandwine.co.../1b340d1ae3fc0a693339355555cdfcfa4971a1e4.pdf

So, taken literally, this means the yeast must increase their population by up to 50x from their typical initial inoculation population before they they will happily make alcohol. On the other hand, if from the get-go you pitch at a rate of 100 to 150 million viable yeast cells per milliliter of must, it seems that then, yes, you can slap on that airlock and the yeast won't complain about making alcohol instead of reproducing.

What does this mean in practice? I think it means that in order to have happy yeast, you need to supply them with oxygen to support their reproduction up until the yeast population is in the range of 100 to 150 million viable yeast cells per milliliter of must. Therefore, the lower the pitch rate, the more oxygen they'll need.

Is this right?

 

[Blacksmith1]

Science... Bah! I shall continue my use of the magic spork. I have absolutely no idea how many yeast per ml I am pitching. I just know that within 24hrs I get decent activity and it starts to cloud up.
By day two I stop messing with it, except to degas, unless I have fruit that needs to be punched down, or some other issue.

 

[NeverDie]

Science... Bah! I shall continue my use of the magic spork. I have absolutely no idea how many yeast per ml I am pitching. I just know that within 24hrs I get decent activity and it starts to cloud up.
By day two I stop messing with it, except to degas, unless I have fruit that needs to be punched down, or some other issue.

My guess would be that the "clouding up" part is an indirect, al beit qualitative, measurement of the yeast population density.

Like you, I previously thought that an air lock was a way of controlling the yeast by forcing them to make alcohol instead of reproducing. But I no longer think that theory is correct. Instead, it now seems that the yeasts' first priority is to reproduce up to a particular population density, and only after that will they make alcohol. Because yeast can reproduce aerobically, cutting off their oxygen prematurely with an airlock in an attempt to force them to make alcohol just means that they'll be reproducing less efficiently than if they still had access to enough oxygen for the more vigorous aerobic reproduction. I suspect that anaerobic reproduction is also what stresses the yeast and produces the undesirable aromas.

 

[RPh_Guy]

It's well known in brewing that aerobic fermentation suppresses ester formation.

 

[Blacksmith1]

What do esters do? Not counting your aunt ester who bakes and knits.

 

[RPh_Guy]

Esters are the main flavor compounds from yeast. They can be desirable or undesirable.

 

[NeverDie]

My initial aeration is the act of stirring in the honey with a lees stirrer and drill. Then an O2 wand at 12 and 24 hrs.

Makes sense! I ordered a 24 inch Anvil O2 wand this morning, and I ordered this oxygen flow meter so I can oxygenate in a consistent way:
https://www.northernbrewer.com/products/oxygenation-upgrade-kit
I'm hoping that by using a fixed flow rate maybe I can discover the right amount of oxygenataion time by practicing on tap water and using an aquarium dissolved oxygen test kit to zero in on 15ppm O2.


I assume you have to de-gass just prior to each of the O2 wand injections at 12 and 24 hours?

 

[Maylar]

I assume you have to de-gass just prior to each of the O2 wand injections at 12 and 24 hours?

Nah. I figure the O2 is displacing the CO2.

 

[NeverDie]

It's well known in brewing that aerobic fermentation suppresses ester formation.

...and maybe HS2 as well. I just completed an experiment where I took a nitrogen deprived mead that was giving off the HS2 smell and, rather than giving it nitrogen, aerated it continuously with an aquarium bubbler. After an hour or so the HS2 smell was completely gone, even after I turned off the aquarium bubbler. However, the HS2 smell returned about an hour or so later. Therefore, I repeated the earlier steps but this time also added Fermaid-O, and, unlike before, after I turned off the aquarium bubbler (about 6 hours ago), the HS2 smell did not return.

So why bother with the aquarium bubbler? Why not just add nitrogen? It's because unless I first clear out the stink, I won't know whether or not the nitrogen addition was sufficient (as evidenced by the stink not returning) or not.

 

[Blacksmith1]

In theory the CO2 should also blow off your rhino farts. I have not tested said theory.

 

[NeverDie]

In theory the CO2 should also blow off your rhino farts. I have not tested said theory.

I thought that maybe (?) in addition to blowing off the rhino farts it was perhaps also shifting the yeast metabolism back to aerobic from anaerobic, and that this perhaps halted the HS2 production, at least while it remained aerobic.

 

[RPh_Guy]

Aeration removes H2S because it reacts with oxygen. Too much aeration contributes to oxidation.

Nitrogen prevents H2S because it prevents the yeast from creating it.

CO2 bubbling also removes H2S because it is volatile, though it may require a lot of CO2 to completely remove it. You may also lose desirable volatile compounds along the way.

 

[NeverDie]

Aeration removes H2S because it reacts with oxygen. Too much aeration contributes to oxidation.

Nitrogen prevents H2S because it prevents the yeast from creating it.

CO2 bubbling also removes H2S because it is volatile, though it may require a lot of CO2 to completely remove it. You may also lose desirable volatile compounds along the way.

In that event, I guess the worst case scenario would be rhino farts in a mead which already had a lot of anti-oxidant additions to it. It might be hard to get rid of them.

 

[NeverDie]

About 30 seconds while stirring the wand around. There is a science behind it, yeast want something like 15 ppm oxygen, but without a DO meter there's no way to know what you have. I just wing it and watch the bubbles...

What about the water in the Go-Ferm solution for rehydrating yeast? Should that be oxygenated as well?

 

[Maylar]

What about the water in the Go-Ferm solution for rehydrating yeast? Should that be oxygenated as well?

No, LOL. The directions say to stir gently.

 

[NeverDie]

I'm now thinking that the easiest and speediest way to de-gas and aerate without without risking a volcanic mead eruption will be to do primary fermentation in an oversized bucket: say 5 gallons of must in a 12.8 gallon HDPE brewer's spigot bucket would, I imagine, give plenty of headroom without having to gingerly ramp up the drill speed and duration. Up to now I had been avoiding plastic fermentation buckets, but now I have a reason to give one a try.

 

[bob1852]

I use plastic buckets for primary for all of my mead batches.

2 gallon buckets for 1 gallon batches and 7.9g buckets for 3-5 gallon batches.

It's much easier to work with nutrients and fruit when you don't have any constrictions in mouth size.

 

[Seamonkey84]

I’m doing a 3 gallons berry BOMM in a 7 gallon bucket. Luckily It’s never close to foaming up to the top. I prob could of easily gotten away with a 5 gallon bucket, but that fruit floats pretty high too.