yeast extract
A vitamin-B-rich mixture made by combining vegetable extract and the extracted liquid of fresh yeast. It ranges in texture from liquid to a light paste. Yeast extract is used as a seasoning and as the base for various products like Marmite and Vegemite.
From The Food Lover's Companion, Fourth edition by Sharon Tyler Herbst and Ron Herbst. Copyright © 2007, 2001, 1995, 1990 by Barron's Educational Series, Inc.