Peruvians on Saturday downed their national cocktail, the pisco sour, with a nationwide celebration of sipping and dancing -- even opening a museum in its honor.

The cocktail, made from a grape-based liquor called pisco, has been made in Peru since the 16th century. Added to it are a squirt or two of fresh lemon juice, sugar, egg white and crushed ice.

Historians say it was devised in 1922 in Lima by an ex-pat American bar owner whose last name was Morris.

On Saturday, all over Lima and elsewhere street stands manned by expert mixers served up pisco sours. Typical Peruvian dishes were served, and people sang and danced.

The drinks are practically sacred here. In 2003, then president Alejandro Toledo declared that the first Saturday in February would from then on be Pisco Sour Day.

And it was mandated that the pisco sour would replace wine and champagne for official toasts at the presidential palace and celebrations at ministries and embassies.

A pisco sour museum was inaugurated Saturday in the city of Paracas, in the southern region of, well, Pisco.