inspissate

To thicken a fluid, in the sense of making it more viscous, especially by boiling, evaporation, or condensation; to condense.

Inspissate at 85°C (moist heat) for 45 min.

Of a fluid: to become more viscous.

Instead of allowing the juice after the incision to inspissate on the capsule, he collected it immediately, and dried it by artificial heat.