Bottling nonexplosive ginger beer?

Howdy folks, this is my first post here.

I recently made another excellent batch of ginger beer and proceeded to bottle it with the goal of having it retain its fizz. I started the batch with appropriate dosage of campden tablets and used Cote des Blanc yeast. It had been bubbling away for a couple days, building itself a good fizz in the heavy recyclable plastic soda bottles we have down here in SouthAm.
Basically my goal was to put it in 900mL glass bottles with proper caps. I have the equipment for proper capping, but I have only done it with flat beverages in the past, not fizzy ones.
I used potassium sorbate (it looks sort of like pastry sprinkles) to stop the fermentation (at least that was the goal), took the recommended dosage for a gallon (3.8L) and quartered it and put that quarter in each bottle. In theory that amount should have been perfect if slightly more than necessary to stop the yeast.
The thing is, though, that it didn't stop the yeast. At least not fast enough to do any good. When I uncap these bottles just a day or two after, they geyser out and you lose half the contents of the bottle. That may be fine for traditional celebratory ginger beer behavior but I prefer drinking my ginger beer rather than wearing it and mopping it up off the floor. Am I doing something wrong? Should I add the sorbate earlier and bottle later? Just how long does it typically take for the sorbate to make the yeast dormant? Should I have dissolved the sorbate in solution first before adding? I want just a good fizz, no geysers

Thanks for your input.

Using sorbate like that is trial and error as far as I know, the easiest way would be to bottle with out sorbate in the glass, minus one bottle in a similar sized plastic bottle. Once the plastic bottle feels hard as a rock put all the soda in the fridge and it should be good.