Electrolysis is not a uniform process. Heavy charging can evolve single bubbles, while light charging can bring forth micro bubbles. So numerous and fine, that the electrolyte starts to look like watered-down milk.
What IS important is the specific gravity. Make sure your maintenance charger has maintained the battery at absolute top level density.
What you do NOT want to see is reddish or dusky gray electrolyte in the barrel of a hydrometer.
If it's all correct...
Electrolyte not reddish or dusky
Density of all cells at maximum, and no excess drop in electrolyte level
You are ready to go camping :)