Irish baking over the centuries has been affected by two main factors. The first is our climate. The influence of the Gulf Stream prevents either great heat in the summer or cold in the winter. As a result, hard wheats, which need such heat and cold, don't prosper. Those wheats make flour with a high gluten content that responds well to being raised with yeast. But soft wheats do grow well here.
The other factor has been the abundance of fuel.Ireland's various medieval overlords could never exercise the tight control over forest land that landowners did in more populous, less wild areas, like England and mainland Europe. This meant that Irish people had less trouble getting their hands on firewood. Where there was no wood, there was almost always heather, and usually turf too. As a result, anyone with a hearthstone could bake at home whenever they wanted to, rather than needing to use a communal bake-oven to conserve fuel.
These two factors encouraged the Irish householder of the past two centuries to bypass yeast for everyday baking. The primary leavening agent became what's now known here as bread soda -- just plain bicarbonate of soda, to US and North American users. Hence the name soda bread. But for a long time, most bread in Ireland was soda bread: "bakery bread" was only available in big cities. Soda bread was made either in a pot or casserole over the fire, or else baked on a bakestone, an iron plate usually rested directly in/on the embers. From these two methods are descended the two main kinds of soda bread eaten in Ireland, both north and south, to the present day.
