The Fresh Loaf

News & Information for Amateur Bakers and Artisan Bread Enthusiasts

Cultivating my own yeast.

Acidique's picture

Cultivating my own yeast.

I began the process of creating my own sourdough starter yesterday.  I am using SourdoLady's wild yeast recipe.  I will be feeding it for the first time today, and I am so excited.   I had no idea it could be so easy to make my own. 

I am still a bit wary of using starter though.  I realize it replaces commercial yeast  in any recipe, but I get a bit confused by some of the directions I read in recipes.  What does it mean when they ask for a starter at a specific hydration?  And how on earth do I measure that?  Additionally, is there an easy way to convert a recipe that calls for instant yeast, or dry-active yeast, into one that uses a starter?

I still have a while before my own starter is even close to being ready, so I will be reading a lot about this until then.  I can't wait to use it!


cranbo's picture

Starter @ specific hydration: 

100% hydration starter means it's fed with a 1-to-1 ratio of flour-to-water by weight. Eg., feed 25g old starter with 100g of flour, 100g of water. 

60% hydration starter means it's fed with a 1-to-0.6 ratio of flour-to-water by weight. Eg., feed 25g old starter with 100g of flour, 60g of water. 

and so on. Make sense?

Conversion from Commercial Yeast:

First, I recommend maintaining your starter at the same ratio of flour to water called by your recipe. This will make it so you have to make fewer adjustments to all your other ingredients. 

For example, if your recipe calls for 500g of flour and 375g of water, 375 / 500 = 0.75 aka 75%. This means your dough is hydrated at 75%. So maintain your starter at the same ratio. For example, feed 25g of old starter with 100g of flour and 75g of water. 

Second, start by using around 10-20% of your total dough weight in starter. So if your final dough weighs 1000g, use between 100-200g of healthy, active starter in place of your yeast. As you get more familiar with how your wild yeast behaves, you can increase or decrease the amount of starter you use, to create a different result. 

Finally, you will need to bump up the salt in your recipe, as well as possibly sugar and other ingredients. Remember, your starter is adding extra flour to your overall recipe, and you need to season it to maintain the same flavor balance. 

Don't forget that a sourdough/wild yeast starter will take a lot longer to leaven bread than commercial yeast (up to 8x longer), so plan your fermentation and baking timings accordingly. 





Acidique's picture

Wow!  That was incredibly helpful. Thank you so much, Cranbo!  The details you gave make complete sense.  It is a lot more simple than I had expected.

You are so kind to have posted all of that for me.  Again, thank you.  I am so grateful!

dabrownman's picture

if you have a stiff starter like I keep in the fridge, is to take 20% of the dough flour, in cranbo's 500 g dough flour case = 100g of levain flour, 75 g of water (75% hydration) and add 1o g of stiff starter to it and build a levain with it that would weigh 185 G.   Once it doubles it is ready to go.

 Deduct the 100 g of flour from the 500 g in the dough getting 400 g and deduct 75 g of water from the 375 g  getting 300g to keep the overall amounts the same.   300/400 is 75% hydration for the dough.   Since you are using the same amount of water and flour as the original recipe, you then can keep all the other ingredients like salt and sugar, butter, etc the same as the original recipe and the total weight is the same if you deduct out the 10 of stiff starter.  The levain would weigh 20.9% of the total weight (adding in the 10 g of seed starter) right in Cranbo's range.