How do I convert my sourdough starter which consists of 1 c. starter to 1 c. water and 1 1/2 cups of flour (and what percentage is that?) to a starter which is 166%?
I am no sourdough expert but that's what I have in the fridge. I use this % to make SD sandwich breads all the time. It works very well for me. I use 1:1 water:flour ratio by volume, not by weight. It's roughly 8 oz of water and 5 oz of flour, I believe. If you begin to feed your starter using the 1:1 ratio, the hydration level will adjust to 166%.
If you want a bit more explanation, here's a link to a previous discussion:
and post that. It is much easier to mathematize. Or did you want a rough estimate?
Ok, rough estimate for cups: ...one cup of (stirred?) starter .... anywhere between 150g and 240g.... One cup of water... between 230g to 250g. 1 1/2 cups flour... between 180g to 300g
Hydration of your starter is... oh well, my head hurts ... experience tells me it is close to 100% hydration, maybe a little less. If you add half a cup of water that would make it aprox. 150% hydration so if you added a tiny splash more water, then it would be about right.
So next time you refresh your starter, use 1 cup starter to 1 5/8 cups of water and 1 1/2 cups flour and let it ripen for a recipe. If you continue to feed for more 166% recipes, reduce the water from 1 5/8 cup to 1 1/2 cup.
Because of the use of volumetric measurements I put my advice under a protective disclaimer. ;)
The math is what makes my head hurt! :-) Let me see if I've got this right. If I start with a cup of my starter (lets say about 9 ounces) and add 8 oz. water and 5 oz. (4.8 oz. to be exact) I will eventually end up with 1.66% starter. Is that right or do I still not get it.
I got the feeling those cups went to fluid oz.(still on volume). Are you using a weight scale or a fluid oz measuring cup? There are two kinds of ounces and they are different. Tricky.
That is 5 oz. (4.8 oz.) flour.
To keep a starter at 166%, feedings consist of a 5:3 ratio of water:flour by weight as 5 ÷ 3 = 1.6666...
So a feeding might be 5 oz water to 3 oz of flour, or 10 water and 6 flour. Any multiple of the 5:3 ratio maintains the 166%, so you could multiply by 1.6 and arrive at your 8 oz water and 4.8 oz flour.
As for what the hydration is of your current starter...it all depends on how you scoop out a cup of flour. As Mini indicates, this can vary wildly, depending on the particular flour, its moisture content and coarseness, and how tightly packed a scoop is. That is why consistency is best achieved through the use of a scale. I once measured out several cups of the same flour and weighed them to get an average. For KAF Organic AP, a cup weighed 122g, Wheatland Organic Whole Wheat was 142g and Hodgson Mill Rye was 139g.
Ignoring minute variations from altitude and temperature, a cup of water is generally accepted to weight 236.6 grams.
Assuming your cup of flour weighs 122g, your starter would be:
1.5 * 122g = 183g
236.6 ÷ 183 = 129.29% hydration.
Given that as a starting hydration, if you mixed 46 grams of your starter with 7.5 grams of water, it would be at 166% hydration.
Alternately, just begin with a small amount of your starter and after several feedings at the 5:3 ratio by weight, it will eventually reach 166% hydration, especially if you discard half for the first several feedings.
Thank you to all who responded to my question. One final question: Does it really matter that much in the end to the flavor of the finished bread whether one uses a cup of 100% starter or 166% starter as long as one adjusts the flour and water for the final dough?