Sourdough with Nutritional Yeast to Make Gluten Bread Rise

Sourdough starter has naturally occurring yeast in it. It is easy to make with wheat flour or rye flour but a little trickier to make gluten free. The nutritional yeast will not add any rising power but will add yeasty flavor. Nutritional yeast is a by product from brewing and may contain wheat/gluten.

Are you intending to make a GF starter? That is 1 learning curve. GF baking is another.

Long answer:

Nutritional yeast is dead so cannot feed on the sugars in the starches (in either wheat or gluten-free flour) and thus cannot create the gas required to cause the dough to rise.

Even longer answer:

Gluten is perfect for bread because it will form a network that is both strong enough to trap the gas produced by the yeast and extensible enough to expand with it, allowing the dough to increase in volume. The oft-used analogy is that gluten forms little balloons in the dough capturing and expanding with the created gases.

Gluten is the gold-standard for this blend of properties (strength and extensibility) and thus any dough made with gluten-free flour will necessarily be less able to capture and expand with the gas. This is the main hurdle that needs to be overcome to get a better rise in gluten-free bread.

Inactive/dead - and thus nutritional - yeast can, however, allow for increased rise in dough but only where gluten is already present.

This is because, for any given baked product, there is an optimum desireable balance between the two properties of extensibility and strength/elasticity. Excessively 'strong' doughs will generally become less extensible and thus be less able to expand with the gases, reducing total possible volume/rise. Think of it like trying to inflate a water ballon compared to a normal balloon.

In those instances, the peptides in inactive/nutritional yeast can be used to help weaken the gluten bonds, essentially trading some of the excess, undesirable strength for greater elasticity, which can improve final volume as well as make the dough easier to shape. This is most helpful when the flour used is not optimal for the intended product. Two examples of this might be using very high-protein flour - 13-14% when making a Neopolitan pizza or French baguette.

Which brings us to the somewhat interesting coda: nutritional yeast can increase rise volume but, unfortunately, that only applies to dough already containing gluten bonds and so it unfortunately does nothing for dough made with gluten-free flour. (Except give it a slightly cheesy taste.)