Gusher? Bottle Bomb?

[Chorgey]

I've been kegging for the last few batches but decided to bottle a Dubbel. Using 2 oz. corn sugar for a 2.5 gallon batch at 70f carbonation. At week 2, I decided to chill and then open a bottle. Carbonation was definitely there but I wanted to try a bottle a week, until 5 weeks.

Today (week 3), I opened a bottle that had a bit of "sediment" in it, it was the 2nd to the last one that I bottled, literally the bottom of the bucket. When I opened it, all of the beer came out at once, not slow but fast and emptied the bottle in a few seconds.

What are the causes for this? I can't see it being over carbed, since I used a NB carb calculator. Infection? but why didn't last weeks bottle have the same problem?

Fermentation was for 21 days, OG 1.063 and a steady FG of 1.012

I placed another bottle in the fridge, going to let it get cold and try it out later tonight.

 

[Amadeo38]

I’ll be optimistic and say perhaps that bottle wasn’t clean, or the fact that it was the end of the bottling bucket, all of the priming sugar had concentrated there. How do you ensure its mixed evenly?

 

[GRJBowers]

I had a similar problem with a beer once. If there is a lot of sediment, they can act as nucleation points for the CO2 in solution causing it to foam like crazy. I'd try chilling another bottle that has less sediment and seeing if that one gushes.

 

[Chorgey]

I’ll be optimistic and say perhaps that bottle wasn’t clean, or the fact that it was the end of the bottling bucket, all of the priming sugar had concentrated there. How do you ensure its mixed evenly?

I used 2 oz. of priming sugar and 16 oz. water in a bottling bucket. Then auto-siphoned the beer into the bucket, with the hose at the bottom, facing in one direction, creating a whirlpool.

 

[Chorgey]

I had a similar problem with a beer once. If there is a lot of sediment, they can act as nucleation points for the CO2 in solution causing it to foam like crazy. I'd try chilling another bottle that has less sediment and seeing if that one gushes.

I grabbed another bottle last night, with much less sediment and placed it in the fridge. Tonight I will open it up and see what happens. There was an exceptional amount of sediment in the last one and I am hoping that was the problem. The foam was ridiculous.

 

[dmtaylor]

More sediment leads to more nucleation sites for CO2, so the more sediment, the more gushers. If you keep most of that stuff out of the bottles, gushers shouldn't happen. I have bottled exclusively for 19 years and for a while I skipped secondary. In more recent years, I have learned the value of secondary and ensuring the beer is very clear before bottling to avoid this.

 

[Chorgey]

I ended up taking the bottle from the fridge and then went outside (didn't want to take any more chances). It turned out great! There wasn't a gusher, only the nice little "fsst" sound. It seems that the general consensus is correct, that the excess amount of sediment has acted as nucleation sites for CO2. Thanks everyone for the help with this!