Did you know
Why a cloudy drink separates, and what an emulsion is actually doing
Flavour oil does not dissolve in water. Every cloudy soft drink on the shelf is a suspension being held in place — and the ring around the neck of the bottle is that suspension losing.
Pour oil into water and it floats. That is the whole problem, and every cloudy beverage is an answer to it.
A beverage emulsion breaks the flavour oil into droplets small enough to stay dispersed and wraps each one in an emulsifier so they do not immediately find each other again. The cloud you see is those droplets scattering light. The flavour you taste is oil that had no business being in water at all.
Two forces are working against you from the moment it is made:
Creaming. Oil is less dense than water, so droplets rise. Slowly, if they are small enough — but a soft drink may sit on a shelf for months. This is what produces the "ringing" you sometimes see as a faint band around the neck of a bottle. Weighting agents exist to close the density gap; smaller droplets slow the rise; both are the emulsion's job, not the flavour's.
Coalescence. Droplets that touch can merge into bigger ones, which rise faster, which touch more. Once it starts it accelerates.
Why this is a formulation question, not a mixing question
Droplet size distribution, the emulsifier system, the density of the oil phase, the acidity and the ionic strength of the finished drink all interact. An emulsion that is stable in a still drink can break in a carbonated one; one that holds at pH 3 can fail at pH 4.
This is why we ask what the finished product is, not just what flavour you want. A stable emulsion is designed for a specific beverage, and "we changed the acid slightly" is enough to matter.
Bring us the brief behind the question.
We make liquid flavourants, emulsions and fragrances to order, in Benoni, for six industries.
Talk to our flavourists