Freeze-dried product is food processed by freezing and then removing ice through sublimation under vacuum, yielding a porous, lightweight ingredient with excellent retention of colour, aroma, nutrients and original shape.
In trade practice
Buyers of freeze-dried berries and herbs pay a significant premium over hot-air-dried equivalents and should verify residual moisture and water activity on each lot, as these determine shelf life and rehydration behaviour. Suppliers must document the lyophilisation cycle parameters and provide certificates of analysis covering moisture, water activity, colour and microbiological limits. A common sourcing confusion is treating freeze-dried and dehydrated products as interchangeable; they differ substantially in texture, solubility and cost. For import into the EU, standard food safety documentation and, where applicable, organic certificates apply.
In a specification
A specification for a freeze-dried ingredient should state the process as lyophilisation or freeze-drying, alongside maximum moisture content, maximum water activity, colour grade, rehydration ratio where relevant, and microbiological limits.