Oh my gush - a bulk priming problem

[philmud]

I just checked on an oatmeal stout I bottled last Monday and noticed that 2 bottles had convex lids. I thought I might just be able to recap 'em, but they were both geysers of beautiful, brown nectar. This is the third or fourth brew in a row where I have lost a couple of bottles this way - no explosions, but always a couple of convex lids and gushers. I had wondered if my bottle washing skills were lacking, but the stout was bottled into brand new plasdene bottles (sanitized of course). Of course another possibility is that my priming sugar is not being distributed evenly. I'm skeptical of that notion though, because I don't think any bottles were undercarbed.
I've checked my priming method here before, but I want to make sure I haven't missed anything. On this occasion I mixed 153g of DME with about 500ml of boiling water and let this cool (covered with sanitized glad wrap). I poured this into an empty fermenter and racked 18L of 3C stout onto it with a siphon. The hose lay in the bottom of the fermenter to avoid splashing but there was plenty of current/circulation. Once done I gave the priming fermenter a gentle swirl and bottled. Everything that comes into contact with beer was sanitized well in fresh starsan.
So, what's the likely culprit? The other possibility I considered is the bottling temperature - should I let it come up to room temp before racking?

 

[manticle]

Bottling temperature is irrelevant.

If you are convinced the solution is properly mixed and you are also convinced the sugar dissolved properly in the first place it may just be the last couple of bottles in each batch.

This happened to me fairly regularly when I bottled due to particulate matter which provides nucleation points. Hoppier beers were especially prone, beers like a dark mild (low gravity, low hopping) generally did not suffer.

What I did was to mark the last 3-4 bottles with an 'X' so I knew not to give those away or place in comps. I also found if I used those as carb testers (so drank earlier than the others) there were no issues.

I am often given bottles from other brewers where this occurs too - it's not an overcarbing problem (that said - watch out for bombs in case you have stuffed up your priming rates or fermentation was unfinished). If it is an overcarb/unfinished ferment, presumably it will be the whole batch. Mine were not overcarbed or liable to explode - just definite boys.

 

[philmud]

Ahh yep, could be the last few, I will start marking them & see - as you say, if they were unfinished ferments, or if I stuffed up my priming rates, they'd all suffer.

 

[going down a hill]

Its quite high in priming sugar. Thats 8.5g/l, I normally don't go over 7g/l. But it depends on how high you ferment the beer and how much fizz you like.

 

[philmud]

Its quite high in priming sugar. Thats 8.5g/l, I normally don't go over 7g/l. But it depends on how high you ferment the beer and how much fizz you like.

It's DME, not dextrose, so I understand you usually use more (I used the Beersmith app calculator for 2.2 vols, same calc recommended 100g of dex). That said, it's the first time I've used DME to prime, so maybe I've overshot. From what I gather, there are a few variables with extract (eg: freshness, fermebtability). Hopefully I'm in the ballpark though, any DME primers have experience with this?

 

[going down a hill]

My bad on the dme.

I have used dme before with the calcs, they come out with the same carbonation compared to using the required amount of table sugar.

 

[carniebrew]

Manticle put me on to the "marking the last few bottles" trick a looong time ago, and I use it religiously when bottling. For me I just add a dot on the lid of the last 3-4 stubbies. Depending on the beer, those stubbies are always carbed first, and often will gush as they've gotten some hop matter mixed in with them as I'm trying to drain as much booze out of the fermenter as I can.

The only other time I've had gushers (from non dot bottles) was when I tried pouring my bulk priming solution into the primary, and stirring carefully. I disturbed the trub, and a lot of the bottles ended up with hop matter in them. From then on I went back to doing what you do, bulk prime into an empty 'bottling bucket' then rack on top of it.

 

[philmud]

The last few bottles thing rings true, I drain the fermenter like a real tight-arse, and there always is a small amount of particulate matter towards the end. I wonder if giving a swirl for the last 5L or so would help, or just create more gushers

Edit: smelling pisstake

 

[carniebrew]

Definitely more fushers!

For really hoppy beers, you could rack to a secondary for a few days before then racking to bulk prime. Or just leave more behind when racking, if you can bring yourself to do it...

 

[manticle]

Keep the stuff at the bottom. Don't swirl.

 

[Mardoo]

Yep, definitely the same experience. Since I started marking the last bottles I now have a better idea of why. And definitely the same situation with the milds versus hoppier beers. Oh yeah, and once I swirled and got 8 gushers at the end, so once again, follow Manticle's advice.

 

[zooesk]

Bottling temperature is irrelevant.

If you are convinced the solution is properly mixed and you are also convinced the sugar dissolved properly in the first place it may just be the last couple of bottles in each batch.

This happened to me fairly regularly when I bottled due to particulate matter which provides nucleation points. Hoppier beers were especially prone, beers like a dark mild (low gravity, low hopping) generally did not suffer.

What I did was to mark the last 3-4 bottles with an 'X' so I knew not to give those away or place in comps. I also found if I used those as carb testers (so drank earlier than the others) there were no issues.

I am often given bottles from other brewers where this occurs too - it's not an overcarbing problem (that said - watch out for bombs in case you have stuffed up your priming rates or fermentation was unfinished). If it is an overcarb/unfinished ferment, presumably it will be the whole batch. Mine were not overcarbed or liable to explode - just definite boys.

 

[MaltyHops]

If you are convinced the solution is properly mixed and you are also convinced the sugar dissolved properly in the first place it may just be the last couple of bottles in each batch.

Granted I only bottle in tall champer bottles (and might feel different if I bottled in stubbies) - as way to improve mixing of priming solution and beer further, I fill bottles halfway until a bit over half the beer in the bottling bucket has gone and then go back and top up the bottles from the start.

I also use these plastic liquer cups (after quick swirls of starsan) to cover bottles after they have their starsan treatment and during bottling to keep floating particulates out - means I don't need to rush.

[zoom]

 

[verysupple]

I'm a bit late on the scene here, but you said you add your DME to boiled water and let it cool. That isn't actually enough to sanitise the DME. It's possible that the odd gusher is from an infection, but unlikely. Even still, I'd be inclined to boil the priming solution for 10 min just to be safe. I mean, what's 10 min compared to the time it takes to brew, ferment, and condition a batch of beer?

 

[philmud]

Yes, that's a fair call VS, I don't think it's the problem though as I have booked my priming sugar before and experienced gushers, and also because it's only a few bottles in each batch. That said, it's a poor practice and you're right, I'd be crying if I lost a batch because of it. I've got a very hop heavy IPA planned for the weekend, will boil my sugar for that one!

 

[pat86]

Hey Prince, have you found a noticeable difference in the amount of bottle trub / material after priming with DME instead of Dex? I want to try it but am not keen on having much more crap in the bottle

 

[philmud]

Hey Prince, have you found a noticeable difference in the amount of bottle trub / material after priming with DME instead of Dex? I want to try it but am not keen on having much more crap in the bottle

Hi Pat, I don't know yet, these are still carbing (were in a cold garage for a few weeks). Pre fermentation, the priming solution was pretty clean looking (no hot break etc), so I'm not expecting any more crud. Someone else may be able to relay their experience.

 

[yum beer]

I use LDM for priming fairly often, mor ethan dex anyway.
You will not notice any more sediment, certainly not significant differences.
Prince I normally go for around 10-11gm a litre for a good lively carb level, 11 for lagers and back it off for ales and stouts.

NOTE: As soon as carb is at a level I'm happy with my bottles all stay in the fridge at 1.8c. so any overcarbing will not occur.
Generally with LDM being 55-60% fermentable you need around 175-180gm LDM to do the same as 100gm Dex.. 10-11g a litre = 55-62g Dex.
I would say that 153gm in 18 litres is going to be on the low side. 8.5g a litre LDM = 4.6-5.1g a litre dex.
I use a carb calculator to get my required amount of dex then convert to LDM.

 

[philmud]

I would say that 153gm in 18 litres is going to be on the low side. 8.5g a litre LDM = 4.6-5.1g a litre dex.
I use a carb calculator to get my required amount of dex then convert to LDM.

Hi Yum, bugger, I hope that's not right because I shot pretty low anyway. I used the Beer Smith App priming calculator which allows you to select DME instead of dex - the dex version seems ok, so fingers crossed they come up ok. I don't mind a low carb in a dark beer, but not too low. I've moved them inside now, so I'll test them again in a week or so.

 

[MikeHell]

Have had the same issue with an oatmeal stout, I primed with dextrose though, so don't think priming substance is the issue. My conclusion is 'calcium oxalate' (google it) may be present, another contender is 'Fusarium' (mould) in the barley, providing all your other processes are up to scratch.

Cheers.