cube-cola 28/4/2005: emulsification report
Production halted after a successful batch 1 due to emulsification issues: the first stage
or the recipe consistently failed (in a complete emulsification of the 8 essential oils, gum arabic and water.
After a fair amount of experimentation we apprehended the limits of our scientific knowledge and contacted an expert,
Dr Peter Barham of H H Wills Physics Laboratory, University of Bristol, for emulsification consultation.
Emulsification meeting 26/04/2005: summary of possibilities (no particular order)
The point of emulsification process is to break up the oil into the smallest possible droplets, each coated
with the emulsification agent.
Emulsification is an all-or-nothing event. If the mixture fails to emulsify to a stable state at the start, no further adding of
ingredients will aid it. Conversely if a mixture has succesfully emulsified (eg. batch 1) & after a period of
time separated, you should be able to re-emulsify it years later by giving it a good go in the blender.
How the ingredients are mixed is critical. The emulsifier should be added very gradually to the oils (or vice versa).
Methods to test:
- Warm gum arabic in water to form a clear fluid, then add the oils from a dropper very slowly (in a high speed blender)
- Dissolve gum arabic in something easier - vodka. The vodka can later be removed from the cola by boiling it off (place the
mixture in a vaccuum to boil it) - this shouldn't harm the oils.
Other variables which could have had an effect in preventing emulsification:
- Batch scale. We were making 5x and 10x batches, which has a dramatic effect on the amount of energy
that needs to be applied at the emulsification stage (5x or 10x) - energy is applied per unit volume and doesn't scale up easily.
Mixing multiple small batches, in a more powerful mixer, should help. (If attempting a large batch
we might want to try a brewing bucket attachment (desgined for mashing fruit) powered by a cordless drill).
- Calcium content of the (bottled) water. Lowest calcium is best
- Acidity of the water: more acidity preferable
- Temperature at which the process took place
- Variation between different batches of gum arabic,
Other things to try:
- Alternate emulsification agents, these include lecethin and powdered (dried) egg white.
The emulsifier should dissolve without any taste, but will affect the texture of the finished product.
- Baking the gum arabic before use. Gum Arabic is made up for long polysaccharide chains of molecules, the
length of the molecules varies. Heating it in an oven for a couple of hours wil make the molecules smaller
and more tractable (soluable)
- Find out what our essential oils are diluted in. Fundamentally they are flavour molecules, dissolved in a neutral oil base.
It's possible to buy food-grade flavour molecules directly. There are natural molecules and nature-identical molecules.