Is there a way to add sour dough starter to this recipe? It has been so successful for me I'd like to try sour dough baguettes.

Converting to sourdough isn't difficult, but it does take some trial and error to get the final texture and taste right.

At it's most basic, you start by making your would-be-sourdough recipe a few times with commercial yeast and get to know the texture of the dough. Then you give a go with your starter. When imitating commercial yeast recipes, I like to make a sponge with my starter the night before (1 or 2 Tbs starter, flour and water - to a total amount of 1/3 the flour/water called for in the original recipe, at the ratios by volume called for in the recipe). I'll add the remaining water/liquid and salt to the sponge, mix well, then add dry ingredients to achieve correct texture (ie, not set weight or volume). The rising time is going to vary drastically depending on your environment, humidity, and the wild yeast culture in your starter. When possible base your actions on your observations, remembering what the original recipe looked and felt like at the different stages.

Keep in mind, unless the bread is sweet (like hot cross buns), I don't add sugar for my sourdough only breads. Sourdough does not need it.

Now, there are several things you can do to adjust your taste, texture and shelf life of your bread. For example the 100% hydration starter that is so popular these days is unnecessarily persnickety (there, I said it, it's my opinion and you don't have to share it). Hydration tables are a modern tool, and are totally awesome if you like geeking-out over sourdough like I do. However, people have been successfully making bread using wild yeast for a few thousand years without hydration tables... For your every-day home cook, you don't need them.

Think about a starter as thick, moderate, or thin. If you can pour it out of your container like a liquid, it's thin. If your spoon stands up in it, then it's thick. You can keep a starter at either of these extremes or somewhere in between. They all have their benefits.

The thicker the starter is, the more it favours the bacteria (sour taste), the thinner the starter is, the more it favours the yeast (sweet taste). The more yeast is active, the faster the bread will rise, the more sour the bread, the slower it will rise, but the longer it will keep without molding.

The starter will have a lot of effect on the flavour of the bread, the sponge will have a lot more effect on how long it takes to rise. So, for example, my standard sourdough bread recipe, I keep a spoon grabbing thick starter, and make a very runny sponge. The bread keeps about 2 to 3 weeks before becoming moldy (on the counter, at room temp, in plastic bag), has a pleasantly sour taste, but only takes a few hours to rise.

For this recipe, I would probably use a medium to runny starter, and make a fairly runny sponge. Any thickness/hydration starter will do, but for trying to imitate the flavour of the original recipe, this is where I would start for a light, sweet tasting sourdough.

For this, I also wouldn't worry about the ratios between flour and liquid, focusing more on the texture of the dough. I would keep the same water and salt by volume (keeping in mind that some of the water will be used in the sponge).

To get those lovely big holes in the bread, I would shape the loaves after the first kneading, and only do one rise before baking. The more we punch down, knead, reshape the dough, the more even and consistent the holes will be (when working with sourdough). For the rustic look, one rise should do it.

Best resource for converting existing recipes is: Baking with Sourdough (Storey's Country Wisdom Bulletin) by Sara Pitzer. If you can't find a copy (it use to be on ebook on amazon, but I don't see it there anymore), then I have a summery of what she says on my blog http://wholewheatfsm.blogspot.ca/2013/03/converting-normal-bread-recipe-to.html

Thanks for this complete explanation. Do you know of a good sourdough recipe? Also, how do you convert this recipe to sourdough only? Thanks

Of course you can.

It's a big help that you are already familiar with the texture of the dough, as the starter will change the moisture content. Depending on how wet you keep your starter, you may need to add less water (for a runny starter) or more flour (for a stiff starter) - or both for a 100% hydration starter.

You can convert the recipe over to only sourdough (easier than you think) or just add a bit of sourdough for flavour. I'll focus on the latter, but let me know if you want to try a full conversion.

If I were adding sourdough for flavour to this recipe, I would add one or two Tbs of starter (dormant, right from the fridge) at the step where we add the flour (after the yeast has activated). Then adjust the flour at kneading if it feels a bit wet.

Why dormant starter? Active (aka room temp, bubbly starter) works well in ideal conditions, but if my commercial yeast isn't extremely fresh (and it seldom is), than my sourdough starter takes over and eats all the yummy yeast-food. This makes the dough take longer to rise, but is more delicious. But if I want the commercial yeast to be the driving force in the bread structure, I try to use starter from my fridge.

If we want to geek out about adding sourdough to a bread for flavour (and know that this is not the popular opinion, but it makes sense when you think about how wild yeast works) is to be careful about temperature. That's not the controversial part, that comes next. Sourdough made from wild yeast (aka, not a bought culture) is yeast that thrives at (your) room temperature, whereas commercial yeast thrives at very specific and generally warmer temperatures. So by being careful to keep the temperature in the ideal commercial yeast range, you can ensure a quick rise and that the commercial yeast dominates... however, if you don't mind a slower rise, you can lower the temperature a degree or ten and the sourdough flavour is more likely to dominate.