Crusʹted Port.

When port is first bottled its fermentation is not complete; in time it precipitates argol on the sides of the bottle, where it forms a crust. Crusted port, therefore, is port which has completed its fermentation.

⁂ The “crust” is composed of argol, tartrate of lime, and colouring matter, thus making the wine more ethereal in quality and lighter in colour.