Variances in over carbing

[cbrobertson]

Not a newby but sometimes I still feel like I am. I BIAB and brew a large variety of styles. Over/under carbing remains an occasional issue. My question is more of curiosity. Sometimes the overcarbed ales foam out of the bottle when I open them, despite tasting just fine (what's left that is). Other times the ale looks normal until I pour then the carbonation explodes. I have to pour a pint into a pitcher and it nearly overflows from the foam. Most recent examples; a pumpkin ale that was a nut brown recipe with pumpkin spices which was the foaming bottle. Just fridged a Kolsch that is doing the former.
So what's the science / reason for one over the other.

 

[heckler73]

1. Use http://www.tastybrew.com/calculators/priming.html

2. Mix well in your bottling bucket and let it sit 30 minutes after mixing your dextrose solution into the bottling bucket - this will help distribute the dextrose throughout the batch.

3. Wait 3 weeks...

4. Profit!

 

[pdxal]

Are you certain your beers are at a stable gravity before bottling?

 

[cbrobertson]

Some of the over carbing comes from rushing the fermentation, poor control of temperature, and others I don't know. I'd say 1 out of 10 batches is my average and I usually have a good guess at why 75% of the time. But let me redirect the course of my query.
Why is it sometimes the beer lets loose of the carb as soon as I pop the top and other times it will hold the carb in suspension until the eddies of pouring release it? It is more of an academic curiosity of the difference than trying to seek out the why's of problem. But the calculator is a cool tool to add to my brewing capabilities. I just got the BrewSmith software for Christmas and am working through the learning curve of the software now. I hope the problem lessens.

 

[pdxal]

Greater amount of overcarbonation=volcano
Lesser amount of overcarbonation=slower release, aided by nucleation points
Gigantic amount of overcarbonation=grenade