The only way was to guess. The new bio-technology industries have also been plagued with bubble trouble. Most experimentation with GM bacteria is carried out on a scale not much bigger than your average home fish tank. The breeding bacteria need oxygen to survive and in small environments it's easy to provide, in some cases using the very same equipment sold in pet stores. However, when the bug growers want to start producing industrial amounts of their micro-organisms, they usually find that their oxygenation systems don't scale up.
Costs rise accordingly.
The food industry is also beholden to the bubble. In snack foods manufactured with high-temperature extruders, the right rate of bubbling can mean the difference between a cheesy puff and an unbreakable cheddar pebble. What they found was that differently-sized bubbles had distinct 'notes', just like different bells or the various pipes on an organ. As bubbles get larger, the tone of their sounds gets lower. The commercial result is StreamTone, a software package that uses microphones to eavesdrop on bubbling fluids.