Ancient wheats like einkorn, emmer, spelt, and Kamut (a brand of Khorasan) can all be used in place of modern wheat flour. That said, a common mistake is to misunderstand the difference between baking with whole grain modern flour vs white modern flour (designed for ideal bread baking). But assuming you are comparing baking with whole grain modern flour versus whole grain ancient grains, the experience will be very similar when baking with spelt and khorasan. Einkorn and emmer require adjustments (less water) because they have weaker gluten and are wetter grains. Quinoa, chia, hemp, buckwheat, amaranth, teff, and millet are gluten-free. They can be used in many types of recipes or included along with other grains but if the recipe is supposed to rise, we wouldn’t recommend substituting all the wheat flour for any of these.