Manna

Manna, also known as ambrosia, Amrit and Soma, was an edible substance consumed by the Isu during the Isu Era. The substance became revered as the food or drink of the gods during human history.

In 2012, Shaun Hastings discovered machines that produced manna in the Grand Temple and tasted it. Finding the taste unappealing, he speculated that the First Civilization might have tasted differently than humans.

Reference

 * Assassin's Creed III