This bread sounds wonderful - but I don't make bread very often and would like to find a substitute for the 100g of leaven. Would yeast work?

On Chad Roberston's recipe for Oat Porridge Bread (http://food52.com/recipes/25384-oat-porridge-bread), someone asked a similar question, and his response was the following: "Hi there - One could definitely use bakers yeast, but the outcome will have quite different flavors and keeping quality, and the way that the wild yeast and lactobacteria work together to leaven the dough (using a natural leaven) makes the final loaf of resulting bread much more easy to digest. Studies over recent years have shown that the microbiology of natural leavened breads around the world vary less according to place and relate more to the time and temperatures (feeding schedules and holding temperatures), and the flour types (whole grain wheat, rye, etc.) with which the cultures are maintained.
A recipe like Jim Lahey's no knead bread is the most effective and simple way to get a decent loaf of bread at home, but the extra steps involved with making a natural leaven are worth a try. In the end, making a natural leaven doesn't require much direct working time, just some patience."