The Fugue

So as not to leave anyone hanging from my last post, here's what I do from beginning to end with regards to calculations when baking sourdough bread.

First, I decide on quantity. I bake a loaf of whole wheat sandwich bread every week or so (sometimes sourdough, sometimes no), and 800g is a good dough weight for that. For a sourdough boule, I aim between 300g and 500g. For experiments and baguettes, 250g or less. For big boules or loaves to fit the more normal size loaf pan, to take to functions for example, I aim at 1kg. The beauty of it all is that I can make whatever amount of bread fits my needs, with a few minor calculations.

Now that we have the dough weight, we need to break it down into the various ingredients. Most ingredients in baking are relative to the flour used, so flour is the first calculation. I divide the total weight by one plus the hydration baker's percentage, i.e. if I want a 66% hydration dough I do flour = dough / 1.66.

Next we need the amount of water. water = flour * hydration. For our 66% hydration bread that's water = flour * 0.66. 66% hydration is a really nice number because not only does it make good bread, it has a good margin of tolerance for measuring mistakes (you can go a little drier or wetter with no worry), and it is easy to do in your head. That's right, 66% is two thirds. 300g flour and 200g water makes 500g dough and it's easy to remember/calculate even without a calculator.

All that's left is the salt and leavening. Salt is about 2% of the flour. I read 1.8% somewhere and it stuck so that's what I use, though I know my measuring is nowhere near that accurate for the amount of dough I make. So 300g * 0.018 = 5.4g. Alas my scale measures 5g increments which is mostly useless for measuring salt, so I asked units what to do:

You have: 1 g
You want: tsp salt
        * 0.16666667
        / 6

Oh, well that's easy to remember, just divide the salt weight by 6. So salt = flour * 0.018/6 teaspoons.

With yeast you just guess. Take a similarly sized recipe and use that much. Bread recipes all vary so much here anyway, and the different kinds of yeast do too. Just remember, more yeast means faster rise and less desirable flavor. Less yeast means slower rise and better flavor.

If you're doing sourdough, I hope you haven't mixed the flour and water yet because there's going to be some adjustment. Decide how much start you want in proportion to your dough. 10% or 20% is easy to do in your head. Now do the same thing with flour and water as above, for your total start amount. Or, be lazy and use 100% hydration start and divide by two (by weight). e.g. for our 500g loaf with 20% inoculation we want 100g start, so that's 50g flour and 50g water (plus a little start from the fridge, about 10g will stick to the side of your container anyway). Subtract the resulting flour and water amounts from the calculated flour and water above (or do the start calculations first).

If you want to add honey, sugar, oil, butter, seeds, whatever else, just follow what a similar-sized recipe calls for or eyeball it. Really the only things to fret here are the flour/water ratio and the flour/salt ratio.

All that probably seems a little overwhelming, which is why my sourdough script and sourdough calculator webpage exist. But if you're lazy/cheap and can memorize a few unchanging equations (but can't memorize a recipe for 5 minutes to save your life), that's how you do it.