Today I am continuing to convert my Finnish Orange Braid to natural yeast. I have been working on it for a while. While working on a recipe, you have to understand patience. You alter one thing at a time, you know, that pesky scientific method, and document the change. You evaluate the change and take notes. This is where the patience comes in. (Last weekend I added in fresh juice, and it had the gummy and over-large crumb feel, and I didn't like it. This week, concentrated frozen juice.)
I cannot reiterate enough, you don't jump to another recipe, give up, or change multiple ingredients all at once, you have to have faith in your process. I have already worked out the starter from yeast flour/water ratio alteration and am happy with that. The dough feels right in my hands, and when I knead it has the same tackiness the commercial yeast version has. Now I am on to the flavoring.
To convert any recipe:
Do I sit down and do math first? No, that isn't my way. That is the way many others do it, and that is probably the way it should be done. I take the yeast version without the yeast, add in the starter, feel the dough. If needed, I weigh the ingredients I add in, feel the dough, and continue until I like the way it kneads and feels.
Not only that, but I have to have a recipe in yeast that I KNOW how it should feel. That way I can work the dough until it is indistinguishable from the one made with yeast. Yes, this does require knowing your dough-to-hand "feel". Then document, document, document! I say: Added x grams/cups, dry, soft, too large of crumb, too dense, etc.
I always keep the same:
Baking times and temperatures
Pans
Kneading times
Deflating methods and amounts
Shaping
I assume two to three times the amount of time for rising BUT
Keep the same height of the rise (I do approx. double)
Please get to know your dough, it is a wondrous thing, a thing of beauty, and a joy to behold. Also, don't forget why you do this, it is fun and enjoyable.