Keeping Particulate Ingredients Suspended in Clear Beverages

Sticking to physics rather than instinct

Settling velocity depends on particle density difference, particle radius, and the viscosity of the continuous phase. Viscosity is the only one of those you control directly, which is why it becomes the standard lever.

The catch is that people over-apply it. A beverage that requires high viscosity to suspend particles will not taste like a beverage. Doubling the thickener to solve a settling problem you could have solved with particle size control is the most common commercial mistake in this category.

Match the approach to particle size

Particles below roughly 100 microns respond well to modest viscosity increases. This is the range where suspended flavour oils, mineral dispersions and fine fibre typically sit.

Above that, viscosity alone becomes impractical. Large fruit pieces, nut fragments and similar inclusions settle fast regardless of how viscous the vehicle is, because their density difference and radius both work against you. For these, controlling the particle size distribution at the processing step — through milling, sieving or homogenisation — is far more effective than reformulating the liquid.

The vehicle must also be stable

Viscosity does not help if the particles are aggregating in the first place. If the suspension is destabilising over time rather than merely settling, you have an emulsion problem, and no amount of thickening will address it.

Check three things in this order: whether an emulsifier is present and adequate for the oil load, whether the oil phase has been properly pre-emulsified before the main mix, and whether your water activity is low enough to permit it. Problems in all three areas present as settling, and the fix is entirely different in each.

Mind the shear conditions in the pack

A shear-thinning hydrocolloid gives low viscosity during filling and line processing, then recovers at rest. That is the behaviour you want — but it means your bench viscosity measurement is not the viscosity the consumer experiences.

More importantly, any shear after filling and before consumption reduces the effective viscosity. Carbonation, agitation in distribution and pouring all contribute. If your product is marginal on the bench it will fail in the market, and you should build in margin rather than testing to the edge.

Practical approach

1. Characterise the particle size distribution, not just the average.
2. Establish the minimum viscosity that keeps settling slower than your shelf life.
3. Check whether that viscosity is acceptable for the product's flavour and mouthfeel.
4. If it is not, fix particle size at processing rather than adding more thickener.
5. Confirm the suspension is emulsification-stable, so you are solving settling rather than aggregation.
6. Validate under realistic shear, not just at rest on the bench.

What we supply

Xanthan gum and guar gum from North American stock, with full specification and documentation available on request. Where your formulation needs emulsifier support alongside the viscosifier, we can supply both and quote the combination.

Tell us your particle size range, target shelf life and whether the product is carbonated — those three facts determine which of the above applies to you.