Weird carbonation

I have a bunch of bottles of a hefeweizen I bottled last month. When I pop the cap off the bottle fizzes over for anywhere from a 30sec to a couple of mins. After it stops fizzing, the beer is pretty much flat.

What would cause this? I have never had this happen before

How long you chilling them before opening them? Co2 dissolves into
colder beer more readily than warm beer. It has to have time also.

If you're getting them cold for a couple days minimum and they're doing this you
may have some infected bottles.

All the Best,
D. White

Some of the bottles were in the fridge for about a week.
That's disappointing that it could be an infection

Does the beer seem rather tasteless? A gusher infection is when bacteria eat up all the residual sugars, leaving the CO2 that is pouring out. The lack of taste would tell you that you have a gusher infection.

Perhaps you used to much bottling sugar and thus perhaps there is no infection.

Was fermentation verified complete?
If it was still fermenting you got the C02 from your priming sugar and from the last of the fermentation, so far more than desired in each bottle.
Are they consistently overcarbed? If your priming sugar wasn't distributed evenly throughout your batch you'd end up with varying levels of carbonation, some under carbed and some over carbed

How much trub is in the bottle? If there's a lot of 'stuff' in the bottom, it'll act like nucleation points and cause gushing. Is there a 'ring' in the neck of the bottle? Or a film?

Mexibilly said:

Was fermentation verified complete?
If it was still fermenting you got the C02 from your priming sugar and from the last of the fermentation, so far more than desired in each bottle.
Are they consistently overcarbed? If your priming sugar wasn't distributed evenly throughout your batch you'd end up with varying levels of carbonation, some under carbed and some over carbed

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They are not consistently overcarbed: some are normal and some are gushers. Interesting point about the priming sugar not being distributed, that may have happened but I always follow the same procedure: pour priming sugar solution into bottling bucket, siphon beer from fermentation bucket to bottling bucket, then bottle via spigot at the bottom.
The beer was left 3weeks and I observed the same gravity reading for two days so I assumed it was finished fermenting.

Perhaps you used to much bottling sugar and thus perhaps there is no infection.

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I used the northern brewer priming sugar calculator for hefeweizen, then scaled it back to around 5oz to prevent the problem I am having. My confusion is after the beer gushes, there is no leftover CO2 in the bottle, it tastes pretty well flat

How much trub is in the bottle? If there's a lot of 'stuff' in the bottom, it'll act like nucleation points and cause gushing. Is there a 'ring' in the neck of the bottle? Or a film?

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There is a layer of fine trub on the bottom of the bottle that I have to wash out, but no more than usual for my bottling process.

Does the beer seem rather tasteless? A gusher infection is when bacteria eat up all the residual sugars, leaving the CO2 that is pouring out. The lack of taste would tell you that you have a gusher infection.

Click to expand...

It was the first time I tried this particular recipe so I can't comment on the outcome of the taste; however, it doesn't have the taste that I would expect from a hefeweizen.