Yeast is a type of fungus that can serve a couple different functions in making food. There are many different species of yeast, but normally when we say “yeast”, we mean Saccharomyces cerevisiae, the type of yeast used in baking bread and fermenting beer and wine.
Paleo and Fermentation
Bread and beer are not Paleo, but depending on your alcohol tolerance, there can be a place for wine, especially red wine. Regardless, there’s nothing wrong with yeast. We eat organisms of all types and sizes, and that includes yeast. Yeast is used to ferment tea into kombucha, cabbage into sauerkraut and kimchi, and milk into kefir, all of which are Paleo-friendly.
Not Necessary But Not Harmful
There’s no need to go out of your way to make sure you get your yeast in, but if you want to include it, it definitely qualifies as a nutrient-dense food.