Volcano Beers / Gushers

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Hopperty

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Why do some beers turn into little volcanos when you take the top off, this beer is about 6 months old, it doesn't seem to be under enormous pressure inside the bottle (the pssst when I take the top off is very normal) But when the top comes off about a third of the contents gently ouse out of the top - see attached video.

and honestly this beer had stood in the fridge all day and was gently taken out!

The beer itself is lovely, yu just have to give it 5 minutes for the froth to turn back into liquid.

 
I don't know if it's always the case, but I have a batch right now where I'm getting gushers.

I was tired when bottling and for some reason bottled immediately after sanitising each bottle rather than leaving the sanitiser in contact with the bottle for a few minutes.

This is the only batch I've ever had gushers with so I'm going to say that there is some kind of infection. The beer still tastes good, but lessons learned.

Also I can tell which will gush as there are some bubbles in the headspace of the bottle before bits opened.
 
I would lean to over carbonation possibly due to bottling before fermentation has finished 100%.
There is the possibility that too much carbing sugar/solution was used.
If the beers taste ok, then there may not be an infection issue as i would have thought the taste would have been spoiled.
The problem is when your bottles go like this, it is impractical, creates a mess and it definitely stirs the sediment up from the bottom of the bottles resulting it in the drink / glass.
It may be an idea to either chill the beers in the fridge before opening, this usually calms the Co2 in the bottles or as soon as you remove the cap, pour into a glass before it can froth over.
 
Good luck with this, I will watch with interest.

I've had gushers on and off for years and never been able to get to the bottom of it exactly. Some common threads
  • Tend to get them in summer but not winter (but not always)
  • All my beers brewed in July and Aug this year gushed (but were just over-carbonated, tasted fine)
  • Sept and Oct brewed beers are back to normal, no gushers yet.
  • I store my bottles in the garage, that gets very hot in summer and seems to re-kick-start the yeast.
  • Before anyone asks, yes I fully ferment out, often bottling after day21 or even day28. And carb with half a teaspoon of sugar per 500ml.
  • I have had infections in the past, these don't appear to be infections.
I do re-use my bottles, and noticed over time that cleaning with a bottling brush did not seem to get them absolutely clean. So I've used a weak bleach solution, and then rinsed well, with the last 3 batches: let's see what happens.
 
You could try venting the ones that might gush. That is, very very gently lift the edge of the cap until you hear it hiss then let go so it re-seals. Do it a couple of times then put it back in the fridge for a while before opening.
 
Gushers occur because there is basically too much CO2 in the bottle (from fermented sugars) and as soon as the cap is removed it forces itself out of solution to achieve a new equilibrium at the lower pressure
So there are normally three reasons for true gushers, probably in this order of likelihood
- bottling before the primary has finished (use your hydrometer or at least ensure it has had more than enough time in the FV) and this includes stuck fermentations restarting in bottle
- overpriming
- a wild yeast infection before bottling
Chilling bottles will help, since it encourages the CO2 to stay in solution, but will only go so far if the beer has suffered one or more of the above.
 
I've had a couple of batches do the slow eruption, I've noted that sometimes it's overcarbed and sometime it's not, but it more often happens with beers with strong head retention and loose sediments that act as nucleation points.

I also tested SG on one of the batches and found that it hadn't shifted down, so it had fully fermented. Could be poor mixing of the priming sugar if you mix in the bottling bucket.
 
1. Wild yeast infection - may or may not affect taste of beer.
2. Fermentation had finished but since bottling the yeast has managed to munch through some of the `unfermentable sugars'.

I've had these on occasion but once you know you've got gushers - refrigeration helps a bit, but when you open a bottle tip it immediately into a jug. A big jug. Let the foam settle and away you go.
There always seems to be a couple of seconds after popping the top before the beer realises it's been liberated and starts foaming. You need to pour the beer in these few seconds to avoid yeast getting dragged up from the bottom.
 
I am going to answer this one with a question: How do you increase the carbonation in under carbonated bottles? You put them somewhere warm for a while!

There's more than one reason for this problem, but storage temperature is the less spoken about. It's warmer here and so this is an issue I had to work on for a long time through a lot of experiments.

This winter I will have access to storage where the beers will be below 20C (winter only), but until then I can only store beers in the fridge.
 
I have an unusual one at the moment - well, the batch has nearly been drunk so I've lived with the problem :laugh8:. It is a MJ Rye IPA kit. There are no off flavours in the beer.

I've bottled in 0.5 litre glass bottles and when opened, there is a nice hiss. I can leave the bottle standing and there is no gushing. So far, so good.

The problem is when I start pouring. I have learned to pour this one slowly (glacier-like) into a jug rather than directly into a glass. As soon as I start to pour, it foams massively into the jug/glass/whatever it is poured into. I can just get the 0.5 litre bottle into a 1.5 litre jug.

It leaves a thin amount of beer and a massive head. If I leave the jug for 10 minutes, it goes back to normal, the head dies down and I can pour it all into a pint glass.

Any ideas on possible causes?
 
I have an unusual one at the moment - well, the batch has nearly been drunk so I've lived with the problem :laugh8:. It is a MJ Rye IPA kit. There are no off flavours in the beer.

I've bottled in 0.5 litre glass bottles and when opened, there is a nice hiss. I can leave the bottle standing and there is no gushing. So far, so good.

The problem is when I start pouring. I have learned to pour this one slowly (glacier-like) into a jug rather than directly into a glass. As soon as I start to pour, it foams massively into the jug/glass/whatever it is poured into. I can just get the 0.5 litre bottle into a 1.5 litre jug.

It leaves a thin amount of beer and a massive head. If I leave the jug for 10 minutes, it goes back to normal, the head dies down and I can pour it all into a pint glass.

Any ideas on possible causes?
What was the priming rate?
Try putting the jug in the fridge before you pour into it.
Is the inside of the jug clean? Or put another way how do you wash your glassware, last with the household washing up and leave to drain/dry, or in the dishwasher, or separately in clean water with detergent followed by a rinse in clean water, and finally a dry/polish with a clean dedicated glasses cloth?
 
I don't think it's my cleaning as this doesn't happen with any of my other beers. I wash all glassware by hand in fresh water and washing up liquid and rinse in cold water then leave to drain.

Checked my notes and I used 90g of brewing sugar in 18 litres, so may be slightly overcarbed. In my early days of kit brewing, I've used 140g in 21 litres and it wasn't as bad as this.

It may be that the bottles were not well sanitised but that would usually be indicated by gushing when opened. All the bottles have reacted the same so it suggests something wrong with the batch/method rather than cleaning of glassware and all the bottles.
 
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One word of warning: if your beers are gushing when you take them out of cold storage DON'T warm them up by leaving them outside the fridge unopened for too long, as the CO2 will exit the beer and put more pressure in the bottle.

I had one hit the kitchen ceiling when I opened it, and on another occasion I left one on the side to warm up whilst I took the wife to her Xmas do, when I got back the bottle had exploded.
 
If of any of interest I do mind reading an article on carbonation where it has been proven that darker beers have more complex sugars due to the malts and these take longer to break down over time. A batch was split into with one half had been given sugar and the other none. These had been left for six months and all had carbonation will the batch with zero sugar added light and the other had a few gushes.
I have yet try this method but there may be some sense to it.
 
One thing I don't think has been mentioned but may be relevant - if your beer has lots of sediment or hop particles then these bits can act as nucleation points around which carbon dioxide can come out of solution and form bubbles. If this is happening to you it might explain why the beer is not exploding and tasting overly fizzy, but it steadily rushing out all the same - the formation of carbon dioxide bubbles might be happening faster than the CO2 can escape out of the neck.
 
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You could try venting the ones that might gush. That is, very very gently lift the edge of the cap until you hear it hiss then let go so it re-seals. Do it a couple of times then put it back in the fridge for a while before opening.

This👆

Root cause could be hard to narrow down. Usually for me it's not factoring in cold crash fermentation temps when calculating priming sugar amounts and then conditioning at higher temps.

I always fill one PET bottle with my bottling batch to give the bad boy a squeeze to see how it's carbonating.

Recently sampled a 11% Weihnachtsbier that I bottled Sept 2019. For Christmas 2019 it had perfect carbonation. What I just opened now could not wait to get out. Just spent 20 mins venting the head space off all the other bottles.

R
 
This👆

Root cause could be hard to narrow down. Usually for me it's not factoring in cold crash fermentation temps when calculating priming sugar amounts and then conditioning at higher temps.

I always fill one PET bottle with my bottling batch to give the bad boy a squeeze to see how it's carbonating.

Recently sampled a 11% Weihnachtsbier that I bottled Sept 2019. For Christmas 2019 it had perfect carbonation. What I just opened now could not wait to get out. Just spent 20 mins venting the head space off all the other bottles.

R
If fermentations are substantially completed when you transfer to a cooler temperature and negligible further CO2 is to be produced by the primary, the beer will not be saturated with CO2 at any temperature less than the final fermentation temperature (where's that extra CO2 coming from?). Only when the beer is returned to the last fermentation temperature will it become saturated again, and that's where the calculators kick in. For that reason I never correct for any crash cooling temperatures, because I always allow my primary fermentations to finish before I transfer, and I have never had any problems with overcarbonation.
 
Should have mentioned that some of the vessels are under pressure........ fermentation is under pressure, allowed to reach terminal gravity, cold crashed to 0.5C whilst still under pressure, transferred to a CO2 purged keg with priming sugar under pressure and then bottled.

This was before I had a counter pressure bottling gun and wanted bottles for competitions, parties etc...

I would have made a terrible mess if I wanted to do this with Wiessbier @ 4.0
 
I’ve finally been lured into posting some thoughts and exposing my ignorance! As such, here’s something to go on the “random, rambling anecdote” pile as opposed to the “rigorously scientific” one…

After bottling for the last couple of years, I seem to have some common threads between beers which over-carbonate or gush (I tend to think of the latter as just a more extreme case of the former which results, tragically, in beer loss…). The latter are fortunately rare for me though and in neither case have any of the beers affected seemingly been spoiled. As it happens, I actually have my worst ever case of gushing ongoing at the moment and have experimented with opening a few samples and recapping after different periods of time to try to find the minimum period of exposure I can get away with to leave a reasonably carbonated beer without oxidising it horribly. Anyway, back to the observations:
  • It tends to affect darker beers more than pale ones. This might link to Gerryjo’s comment but might also be connected to the fact that I don’t tend to cold crash or add gelatine for clarity to these
  • Beers that have been cold crashed/gelatined generally have a good carbonation level after 3 weeks but tend to continue to creep upward if stored for longer periods
  • Beers with a higher differential between fermentation and bottle conditioning temperatures are more likely to be affected (i.e. whilst FG may level out in the fermenter at 19C, if bottle conditioned at 23C, the yeast seem to be able to get more out of the original wort as well as the priming sugar whilst conditioning)
  • The amount of dextrose I need for priming does seem to be affected by yeast strain (some highly flocculent yeasts – especially San Diego Super – seem to need a bit more fuel, especially if also cold crashed)
Some of these factors might naturally counteract one another. For instance, I’ll generally cold crash/gelatine a pale beer fermented at a lower temperature. This combination seems to negate any initial over-carbing during conditioning in the warm but still allows for the gradual increase in carbonation over time

I’ve just started experimenting with bringing all beers into the room in which they’ll be conditioned for a couple of days at the end of primary fermentation in an attempt to drive out any last shreds of attenuation prior to bottling. I'm also going to start cold crashing even the darker beers. This means that I’ll be putting all beers through the same process to see if this helps narrow the list of remaining factors

If any of this wild speculation is borne out by this testing, I may have to accept that there’s a trade-off between cold crashing and conditioning period (i.e. if I want to have a beer ready after 3 weeks of conditioning but not experience this alleged “carbonation creep” later, I may not be able to cold crash – by the same token, if cold crashing, I’d have to prime with a lower amount of sugar and be prepared to wait longer for the reward). Jury’s still out at this stage though…
 

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