What You Need to Know
During primary drying, ice sublimates directly to vapor at temperatures between –30 °C and –40 °C and pressures of 0.1–0.2 mbar, preserving heat‑sensitive volatiles. Secondary drying at 20–30 °C removes bound water to reach <1 % residual moisture, ensuring a stable, low‑moisture product with intensified taste while maintaining sensory quality.
The Science
Primary Reaction
sublimation of ice to vapor under reduced pressure