Thanks for the tip on WLP099..
There are many reasons for bottle bombs:
Make sure your beer is fully attenuated before bottling.
Use a priming sugar calculator. Make sure you have all the details right:
- Volume of beer to bottle
- Temperature of the beer (will affect residual co2 content from fermentation)
- Measure your sugar by weight, much more precise
Mix your sugar very well in the bottling bucket. If you just add the dextrose powder, chances are it will not all dissolve and the last bottles will have a huge amount of sugars.. + the dextrose is not sterilized.. What I do is I dissolve the sugar in a cup or two of boiling water to create a syrup. Chill it and then mix. Since the sugar will be dissolved, it will mix much more evenly.
Finally, watch for contamination, which can cause gushers as the beasties continue to work on residual sugars in the bottle..
Don't worry I'm sure you are going to laugh about this story in a little while...