Using this technique, but mixing the grain with ale can result in a dough that will rise when left for a while. Perhaps this is how leavened bread was discovered? Prehistoric people of 3000 years ago were using types of wheat such as emmer and einkorn to make bread. This type of wheat has a low gluten content and will not rise as much as modern wheat varieties. Bead can be baked flat on hot stones or in a clay oven to form round loaves.
In Roman times, spelt wheat was the preferred crop, giving a good crop yield and producing a distinctly nutty flavoured loaf. The Romans did not use salt in bread (that came later) but would add honey to flavour the loaves, which made the bread a little sweet for modern tastes.
Clubwheat was used to make a plain loaf in medieval times. Other flours such as vetch, barley, oat and pea were also used. Spelt wheat would be available for the wealthy. Some unscrupulous traders were known to add chalk dust to flour to increase the profit margins.
Modern wheat has been developed as a crop for about 800 years and the latest varieties give a high yield of high gluten grain which is ideal for making light and well structure modern loaves. The grain can be wholemeal, or sieved to give white flour and bran. White flour has a high gluten content, but lacks some of the nutrients of wholemeal flour.