Glossary
Emulsion
What is a flavor emulsion?
Oily flavor broken into tiny droplets and held in water by a gum. Used when an oil-based flavor has to go into a drink, or when you want the drink to look cloudy.
Citrus oils, most spice extracts and a lot of heavy fruit components are oil-based. Put them straight into a drink and they float, leave a ring round the neck of the bottle, and taste different from the first sip to the last. An emulsion breaks them into droplets small enough to stay suspended.
Emulsions do two jobs, and it is worth knowing which one you are buying:
- Flavor emulsions deliver flavor.
- Cloud emulsions deliver the look — the opacity people read as "juice" — with little or no flavor.
The two ways they fail
Ringing is the visible oil ring at the top. It happens because oil is lighter than water and floats. You fix it by making the oil phase heavier with a weighting agent, and by making the droplets smaller so they rise more slowly.
Separating is the droplets merging back together over months. That comes down to the emulsifier, the droplet sizes, and how much the product gets shaken about on the way to the shelf.
Both get worse when the temperature keeps changing, so a shelf life test held at a steady 20 °C will make your product look more stable than it is.