Treating Green Bottles

Green bottles have always been?something of a vexed question. Once?the filled bottle leaves your plant, you?have little control over what happens?to it, particularly when it is empty and?left for collection.

Bottles left in sunlight and a warm?environment are susceptible to algal?growth. When green bottles are?returned for filling what do you do??On the one hand you can throw them?away, but if the algal growth is not too?bad perhaps they can be cleaned?and returned to the wash/fill cycle.

Green bottles should never be put?through the normal washing process,?otherwise the bottlewasher quickly?becomes contaminated with algae.?A separate process is required using?good mechanical action, preferably?with brushes, and a strong bleaching?detergent. Good rinsing is essential.

Simple home-made rigs can be set up to carry out?this task and the best detergent to?use is a low foam chlorinated alkali at?a temperature of about 55 deg C. The?temperature must not exceed 60 deg C?otherwise the chlorinated product will?degrade and cause corrosion, even of?stainless steel.

Commercial pre-washers are available and these will take one or two bottles for pre-washing, using intense spray and brushing actions which will remove the algae.

In the summer months the "green-bottle" phenomenon is at its worst and even a few hours in direct sunlight at summer temperatures can germinate algal spores which have floated into empty bottles awaiting collection.